+1 same applies to your 135i:
1. How many types of warranties are there? And what do they cover? Many...various things.Call a dealer and aftermarket companies (Carchex was recommended in bimmerforums)
2. Is there any-type of factory warranty available through BMW?(If the seller did not purchase a warranty?)Yes, call your local dealer or and carchex.
3. There are a few known issues that I know of; fuel pump, HFPF failure, etc. Does BMW cover any of these recalls/problems? If so, which recalls do they cover? And will they charge me for small fees? Yes, HPFP 10yrs/120K mi. Turbo/wastegates 8yrs/82K mi. They shouldn't but some dealers try trouble shooting which requires charges if you are out of factory warranty.
4. If BMW doesn't, will the warranty cover the recalls/ other known issues?The warranties above are separate versus your factory warranty.Really depends on the age of the car. factory warranty is 4 yrs/50K mi.
5. Will any of these recalls/known issues cause the car to be immobile?(Not able to be driven, until fixed)Yes, HPFP.
6. What are the needed services for the mileage timeline?(30k, 60k, 100k? I believe.) And when will the stock turbos need to be replaced? Does warranty cover this?Google Mike Miller BMW...turbos will need to be replaced at some point, depends on the age of the car, and the condition of the turbos.
7.. Starting from recalls to other known issues; in a list, how much will they cost to fix?Again, depends on your factory warranty and how good your dealer is at trouble shooting. Many follow procedures for trouble shooting so if you are out of warranty it will cost you.
FYI...there is no definitive answer for some of the questions you are asking. Expect to $$$ on potential repairs if you are buying used. Doing it yourself will save you $$$ in the long run. GL