When my tinting was done I had an issue with my 08 Coupe 3.5SE on the rear window...
The top 6 inches or so where the dot matrix is has issues staying flat. You end up with white blotches and whatnot in areas.
My tinter sandpapered the dot matrix down a bit so the tint would make better contact.
When I picked my car up there was a bunch of white blotches still, although now-- a week or so later most of it has gone away and it looks clean as hell! There is only a tad bit of white and you really need to be up close to see it.
You mentioned bubbles-- there may be a few small bubbles at first the day of the install or even up to a few days later.. but if the bubbles remain after 3 days or more it is definitely a sign of a crappy job and I highly recommend bringing your vehicle back.
In regards to your legalities questions...
http://www.tintcenter.com/laws/NY/
Your tint must allow 70% or more light transmission in to be legal in NY and PA. That means 70% tint is legal. Anything lower than 70% tint is technically illegal.
Usually cops won't be bothered with anything 35% or higher since 35% can be fairly easily looked through... it's all about the safety of the officer and other officers and if they can look into your vehicle or not incase they'd have to pull you over... hope that makes sense.
I got 18% on my rear window and 35% on my 1/4 windows and my fronts... the 1/4 windows look much darker (almost 18% like the rear due to there not being a lot of light back there) and the front windows are just light enough to be able to look in incase a cop had any issues...
I haven't had any problems yet, if worst comes to worst and you get pulled over-- if your tint is really low/dark roll all your windows down and put your hands on the steering wheel or out the window as a means of communicating to the officer that you are unarmed and not dangerous.
Regardless of all of that 35% should be more than fine as long as you don't run into any PITA cops... but as my experience has shown-- they'll respect you if you respect them.