Low Action for Jaguar

How long is a piece of string?

It all depends. How the neck is, how the frets are, was the neck pocket cut correctly? Anything can be fixed, and I guess a lot depends on how low you need.

Hi, 16mm,

I'm not sure why low action is so important if your 'bad' hand is the picking one? Exploring lighter string gauges I can see, but I don't get the 'action' angle.

I'm with boxboy low action isn't going to help your picking hand anyway I can see.

Lower action isn't going to help attack but that is accounting for a typical approach, which we aren't. But if your trying get the most attack possible out of the fretting hand by using tapping, hammer-on's and other techniques I can see how lower action might be on the right track.
One benefit of the Jag is it has a shorter scale than most guitars so the strings are under less tension and that will help with the right hand. You might want to think about an even shorter scale guitar like a mustang. There are some other things that would help you get the most volume and playability relying mostly on your fretting hand:
A bolt on maple neck with maple fretboard, bolt on necks have a faster initial response and maple is the brightest of normal wood options for fret board materials. (another vote for the mustang)
I think, but I'm not sure that smaller frets would also have the most benefit, particularly the new knife-edge frets because of the precision involved (but that might not be an expense worth taking and I have never actually played them). Larger frets are great for fast notes and bends but fast notes require right hand assistance.
I wouldn't go Fender vintage on the fretboard radius, but I wouldn't go flat either even though it would suit left hand technique more. You'll probably want some where between 9 and 11 inches.
And for right hand tapping and other techniques you'll probably want the largest strings you can deal with because volume and sustain are going to be your biggest allies.
The one thing I think will help you more than anything is Joe Barden DG signature pickups. They are ultra high fidelity, so much so that most players can not use them because they magnify everything and love making sloppy playing sound really really sloppy. Now your probably thinking, "hey pickups that will make me sound worse, thanks a lot jerk." You're welcome. These are the only pickups I can think of that could literally put transparent volume into the slightest right hand. The drawback is you'll have to work harder at getting solid notes out of your left hand but lets face it, from your own description you're already starting on the back foot. Oh, and they are stupid expensive. Like $500 a set. But if that's something your interested in PM and I'll see if there are comparable pickups out there.

I get s1120's point...yeah...there's no end to getting it right.

I've got a '73 Jaguar and, yes...the neck's thinner than most axes, so maybe that'll help. Still, I do think that perseverance is all you need to add to the equation, matey.

Cat

I agree with all. Lowering your action is to help the left hand when forming chords (bending perpendicular to the fret board) . Careful that going to smaller scale guitar will, most likely, get your strings looser for the same gauge set. That will get buzzing to occur if you attack strings heavily. Strings in smaller scale guitar are under less tension when tuned to normal tuning pitch. I currently have LP copy guitar (24 3/4") scale, and I find the strings looser and buzz when I lower the action to less than 2mm, and 1.5 mm on the E and e respectively. This link is very useful: http://www.12fret.com/content/2011/07/11/scale-lengths/