Agreed, these are terrible scans or you have very old, expired, stored next to a heater film. Can't help you on the labs, but I suggest you buy a yellow K2 filter (shouldn't be very much) to make the clouds stand out better on the sky. The third picture is still a light leak (somewhere, either in the camera, in loading or in processing, light is getting to the film) but unless it shows up repeatably, it is very difficult to track down. If it is in the camera, it will be on multiple frames; if it is in the loading/unloading, it usually affect first or last couple of frames; if it is in the lab, it will show up a random times and switching labs will confirm.
Amateur, from the French for "lover of". I have been shooting for 25 years and consider myself an amateur.