Hi Janet
Hope these answers will help
1- Yes you can apply for residence permit when you are here with your touristic visa.
How you can apply : Inspector explained it very good , its sticky at the beginning of this topic but I have to tell you will need a person who speaks good Turkish when you are collecting the papers and making the payments , you can ask help from your estate agency.
2- Although I couldnt understand this question (my English sometimes is not enough ),I will try to answer how I understood. You have to proove that you have enough money to live in Turkey , to give the photocopy of bank notebook which has at least 1.000 GBP is enough.
3- If you find a reliable estate agency (most of estate agencies here , are reliable)no need to worry.For the peace of your mind you can use a solicitor service also.