Lots of Splotches in the Metallic- Should I Cut My Losses And Pay The Man?

If its been cleared, I don't really see a reason to strip it either. Depends on how poorly that base was sprayed, and wonder if there is going to be an issue with the bond of the clearcoat to it. But no reason you couldn't otherwise sand the clear smooth, shoot some epoxy on any cutthroughs you have, and reshoot base on top.
Sounds like you already bought the paint, but you may want to go with a better line and a polyester based basecoat. I haven't used nason, but heard others say many times on here how the metallic control in nason is not the best, and how tricky it can be to spray. I have used the nason clearcoat a few times, and didn't think that is too bad, layed down well for me anyways. But the 496 unless you use slow reducer and activator will set up aweful quick. I remember having a bear of a time shooting some metallics in omni many many years ago, when I was still fairly new to painting, as well as many colors that coverage was pitiful.This is just another area where using a better base usually pays off, coverage and ease of use.
I would surely practice some more before respraying the car to figure out what your doing wrong. Get you gun dialed in and if it ends up being needed, how to shoot a mist coat to help even a metallic. But you still will need to be able to get the base down medium wet, and shoot your mist coat soon after while the previously sprayed stuff will still accept it, or else you could again end up with a dry, rough or cobby base, and possible adhesion problems in the future between the base and clearcoat.
I don't know if you have to use different product then other areas being in california, but seems to me, the more they change the voc laws and make them conform to tougher standards, the crappier the product becomes.

Exactly, your clearcoat is now like a sealer to spray on, and will make a good surface to paint on, provided it is sprayed decent, or at least sanded fairly flat. And being the basecoat color shows through, coverage of your new base should be somewhat easy to achieve. Your new coats of base should cover the cloudiness, and clear up the blotchiness of the old metallic, provided you can spray the new stuff well.
I wouldn't go 400 for a metallic. Around 600 should be in the ballpark. You will want to avoid cutting through your clear into the base underneath if you can help it, which could give you other headaches when you shoot new base/solvents over it.

The chromabase should be a bit easier shooting a metallic. The knock on chromabase seems to be for a pricier line, it seems to have more coverage issues then other brands comparable lines, so your best off shooting it over what duponts recommended shade of valueshade primer/sealer. Being as you already have shot your color, and are reshooting for your blotchy metallic and cloudiness issues, coverage really shouldn't be an issue.

Kinda surprised nobody said anything about Nason thru a 1.3 tip.

Main reason the "small" stuff looked good and then on the large areas splotched or DRY SPRAYED.
With a 1.3 you have to go slow and deliberate on large areas or complete vehicles as your not putting out enough product to COVER a LARGE area at the SPEED you THINK you should go at. Your pattern is going to be short and if you open up the fluid to compensate,your going to splotch or peel the base.
Add more air and your wasting paint. Your only going to get a SPECIFIC,CORRECT pattern out of that gun/tip combo. FIND IT!!!!
Do test sprays on paper 6-8" out till you get the gun making the best,tallest patern.Generally full open on the FAN knob or a 1/4 turn in from open and 2 3/4 on the fluid to start and I bet you won't be far from that when it's all said and done.
Air PSI. WHAT does the GUN recommend??? It have a REGULATOR??
Do NOT use a choke/cheater valve to adjust the psi on an HVLP gun.you WANT air FLOW and only a regulator can do that.
Make a pass on a lower rocker or someplace inconspicious and adjust the fliud to compensate for your speed in order to get decient coverage,likely a 1/4 turn more out on the fluid,your pass's will also be slower than you think.
OVERLAP. 60-75% for metallics.Think about this for a minuite.
When you do your test sprays,MEASURE the total HEIGHT of the pattern when it's right. Say it's 6",You realize you'll only move the gun approx 2" up or down for 75% overlap for the NEXT pass????.
Personally,I'd be looking for a 1.4 nozzle for that gun if you plan on painting a complete and ESPECALLY for the CLEAR.
Also,What base are you planning on this time?
Reason is,
If you plan on Chroma,I would go 800 on the final sand of the clear or red scotch pad the entire car because Chromabase won't fill scratchs for crap and your sanding HAS to be GOOD.Yes it IS an "easier" spraying base for metallics BUT, it's piss thin and will fall into ANY hole you have on the surface.
Your essentially doing a "blend" repair job shooting over the clear job and with it being "fresh" clear,your prone to solvent sand scratch swelling.
Nason on the other hand is thicker and does FILL better BUT,is a tougher shoot metallic wise.
Either way,allow LONGER flash time between coats.
When sprayig Chroma I will either do as above or shoot a coat of intercoat clear FIRST as this will fill any sanding scratchs and make the metallic base smoother and easier to lay down.

Guys, thanks for all the great advice.
Bee4Mee, you're right about the 1.3 tip. I did some test sprays on an old door and the 1.3 tip worked better than the 1.4 tip but things were different on a horizontal surface.
I do have a regulator at the gun that ran best at 35psi. My compressor had no trouble keeping up.
When I was spraying a large surface, I had the fluid set wide open and actually had to slow my passes down or the paint went on too dry and thin and the light and heavy spots would get worse. The spray pattern was set 3/4 of a turn open from fully closed. If I opened it further, the center of the pattern would be light and the edges heavy, just the opposite if it was closed more than 3/4 of a turn. I was holding the gun about 6"-8" from the surface.
I tried the criss cross pattern on the hood but it actually made the blen even worse.
I was following the manufacturers recommendation of 1:1 ratio with the reducer. Maybe I should have adjusted that.
I only messed with the 1.4 tip on both the base and the clear when I was 1st dialing the gun in but the 1.3 seemed to work better at the time.
I only over lapped 50%, maybe I should had done 75%.
The sun is shining right now, so I think I'll pull it outside and see what it looks like.
I took the gun apart after every session and saw no paint buildup inside. I did have to tighten the needle packing when I 1st set up the gun, after that, I had no issues with splatter.
You'll see that I only have 3 or 4 posts but I've been reading on this forum since around June. It's a great site.

so your saying you had the fluid wfo and the fan at 3/4 open?
Something is wrong here.
I got to do some thinking about this as to why,could be the air cap holes next to the nozzle opening are blocked and the fan is blowing it out.

Thought a little about it.
You set the gun up EXACTLY as I said previously and do some test sprays and give us the results.Full pull on the trigger for 1 second and release.
If it's not "close",you have gun issues.

You cut the fan off and with the fluid wfo,should have one,nasty,running,circle,at your spraying distance.
You open the fan back up to full with full fluid and you'll likely blow it out as it's WAY too WET from all the fluid and the fan is just helping push it out.

I've not sprayed any of the low VOC stuff so I have no idea what it's consistency is.I've sprayed about everything thru most any style gun and ALWAYS been able to achieve a good pattern IF the GUN if functioning properly and the AIR is the proper amount REQUIRED for the gun used.
Yeah,I may have to adjust the product ratio for the prefered finish due to the gun's "characteristics",But still with those base settings,had a good starting point.