1) How can I tell if my car has an altered suspension? I'm 99% sure it's stock but a shop denied me of a warranty on my tires b/c I'm "lowered". My car has the factory body kit and is the sports package. I can barely fit two fingers in the wheel gap up front and one finger in the wheel gap in the rear. The shop said, "You probably have altered spindles or eibach springs". I like how he knew what brand and he never put my car on a lift.
Well, being that low (two fingers), you might...but I am not sure what the OEM "sport package" includes, so that might explain the lowered ride height. Since they didn't put it on the lift, and visually prove that you have an aftermarket suspension, I would speak with a manager. If you do though, then I guess they could have a valid argument. Although it's a manufacturers warranty, so what does a shop give a crap about it? Are you able to jack your car up, and check the springs/shocks, if aftermarket they should have some sort of markings, brand name or something.
2) Would you buy two tires (used for only 1 summer) if they are about 3 years old? They are Falken Azenis ST115s and sat stacked in a garage not on wheels. A buddy offered me 75 for the pair. That beats 90 per in my book if they're safe. I'm looking to know if the material could be broken down and weak at this point.
You can check the tread wear, and visually inspect for any type of dry rotting/cracking. Theoretically, they should be fine, but it's hard to say without seeing them, or knowing how they were used in that 1 year. Guy could have beat on them, or had alignment issues, which would cause un-even wear. If your that concerened, Tire Rack has Kumho Ecsta ASX's (15") for $49/ea., and offer a $40 rebate if you get al full set. Just an inexpensive option, and they will come with a manufacturers warranty.
3) If BF Goodrich tells me that their policy is that the customer buys replacements based on a decided prorated price from the dealer and BFG refunds the dealer and the dealer tells me thats not how things work (two different shops have told me that)... what should I do? The tire has 90% tread life left so I want to get a new one to at least sell it. I just had a guy tell me that my tire with 10k miles and under two years of life has a cracked sidewall b/c of normal wear. When I say cracked, I mean, 100% around the sidewall and you can lift up rubber a good bit.
Are you the original purchaser of these tires? Accroding to the BFG warranty info (http://www.bfgoodrichtires.com/asset...fgwarranty.pdf), as long as the tires were rotated at proper intervals, and the wheels were kept in proper balance/alignment...you should be covered. Not sure if it's really worth the hassle, but you'll most likely have to contact BFG again, and have them contact the shop in question to arrange something. They might even require you to send the tires directly to BFG for inspection, so it's up to you if you want to got through that. Overall, it sounds like the shops are being pricks, but that typical.
How bad is it to have Falken's up front and BFG in the rear (or should I put the newest tread in the rear?)
I guess it's fine, as long as everything is balanced properly, and the tread patterns are too drastically different (ie. drag slicks up front, mud boggers in the rear 
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