The dark spots on the first picture, couldn't that be underdeveloped spots due to air bubbles?
Picture 2 looks to me not as light leak (necessarily), but rather over developed edges due to inproper agitation.

I have for many years used Fomapan 100 as 4x5/5x7 and 8x10 (unfortunately not in 35 mm or 120, but should be the same emulsion); the only problem I have encountered was some years ago when it was suddenly necessary to prewet (2 minutes) the film sheets bevore developing.
I have had no problem with ordninary stop bath, and my developers have been Rodinal (1+50), D-76 (konc or 1+1) and D-23 (konc or 1+1).

I would recommend quite vigorious agitation the first minute, and then the same vigorious agitation some 10-15 seconds each second or third minute.
(In my experience the most important thing with agitation is not that it is performed very often, but when it is performed it should be done vigoriously, in a random pattern, in order to get rid of the all the used chemicals, and for new fresh chemicals to enter the emulsion - it may work to agitate very cautiously but it's risky and my yield uneven development.)

Your problems may not necessarily be due to the film, give it another try!

Good luck!