Welcome to the forum...
Did you have a PPI before purchasing the vehicle? If so, whoever did it, didn't do a very good job since all these items just don't need work all of the sudden. If you didn't have a PPI, you should have to be aware the work that is needed prior to purchasing it.
None of these items will show up in the idrive except maybe the brakes. A independent shop could be 1/2 the price of the dealer. Sorry I don't know of any mechanics to refer you to since I do all my own work, but you could look up
bimrs.org to see if there's something in your area. Not sure about a "affordable yet effective" tech since many times you get what you pay for
BTW - Many shops don't want to install parts you bring then since they make a profit off selling the parts as well as them having to deal with parts that may not be the correct ones.