I'll take a shot at your questions.
1. Rollins had to be on the roster July 4th. As Rule 5, Rollins must be on the 25 man roster every day he is able. The 80 game suspension ended yeaterday, so he is here. What I can not answer is what happens if Rollins stays on roster for all the remaining games. I believe a player must spend at least 100 games on the 25 man roster (versus being on DL). Since Rollins is the first Rule 5 player to get suspended, I do not know if Rollins MUST start on 25 man roster to begin next year, or if the Mariners can start treating him like Lucas Luetge... who is still on the 40 man roster for some reason.
2. I guess is your questions are either A. too tough to ask in a brief sentence OR B. sometimes seem obvious or rhetorical
3. This is your classis question. No true right or wrong answer, and no way to answer intelligently with a brief answer. The best way I can answer is that the Mariners have 4 or 5 top 100 players in the MLB on the roster, and maybe even 8 in the top 200 players but then - NOBODY in the next top players from 201 to 500...and then the Mariners have probably 30 guys or more who are best characterized as players who are excellent roles players that should be players 15-25 on your roster. The middle part of this roster is just YUCK, and it is almost impossible to identify who should stay and who should go... but maybe a good manager or GM or coaching staff could figure it out given 18 months.