Many questions in there Caz
I've used most of the big ones in one way or another and think that the most important thing is your time, wasting away while you wait to be served. I like Alper at Fortis Bank, also because he helps us with matters here on CBF. I also never had any problems with HSBC. I lost much of my life standing around in Finans Bank, and would have gladly taken my own life if I could have found a sharp enough envelope opener in Deniz Bank.
For the same reason, although you don't need to 'internet bank', it will save you a lot of time. Transferring between accounts etc can be done easily and quickly, meaning you don't have to waste a whole morning waiting.
For the questions about investing 50k, there are far better qualified people to answer that than me
