Strangely enough, I passed the St. Mark's Mafia Rampage AFTER I finished the story, as in my 100% Playthrough with 7 proof vehicles, I actually did the 20 Rampages LAST for 100% Completion. I must of been lucky as hell, cuz I passed it first try...On the way back ON FOOT running through St. Marks I got SO close to dying...0 Armor and like 15 Health, but luckily I got back, saved, and didn't die as I like to keep the stats as clean as possible.
That's actually why I like VC, everything you said, is why I also like VC, but as a whole the atmosphere of the game just won't "make" the game for me. There is many more compotents to the game than that....As for the map, for me, it's the worst one. Especially in Little Haiti and Havana, etc...The roads are all over the place and don't make much sense to me, lol...The long straight aways on Ocean Beach and on the West Island as well, can be found in GTA III and LCS, too. They have some long straight aways as well. I usually would go to the long straight roads in III and LCS to get my point of view back as to where I was going and maneuvered from there.