You did not specify if you wanted to shoot color or B&W. Your mention of slide makes me think you want to shoot in color, not B&W.
In favor of color negative film. You can still find places that will do 1 hour processing of color negative film, but NOT color slide film nor B&W.
A yellow filter is only good if he is shooting B&W.
I shoot slide film, and the thing with slide is that it does not forgive your exposure mistakes, you don't have a 2nd chance to salvage it. What it does do is force you to learn to expose correctly.
I agree with you about 36x rolls. If you don't know how much you will shoot, which most of the time you won't, so you would probably load a 36x roll.
If film price is like jspillane quoted for Fuji Superia at $2.50 a roll, I agree, just buy 36x rolls and buy it in bulk.