So, I only read a few paragraphs. The swimming in VCS wasn't all that great, you had one minute of swimming time, and if you wanted infinite swimming, you had to complete the side missions. But it was fun doing them though. If they were to make another GTA for the PSP, I am sure that it will be better then LCS and VCS, R* learn from their mistakes.
Even though you need to complete the side missions for Infinite Swimming, I still liked it, being able to swim in this came shows that R* do bring us what we want in follow-ups to previous games.