i think i've run into the same issue in further probing with Road Fighter that you describe with the rippling effect and i don't have a solution for it either. there again i've been doing a lot that i haven't been uploading as well because they are too messy to show and have run into some weirdness that i can't solve due to game tile weirdness (exerion, rad racer, Mystery World Dizzy).
As for the first question, there's a lot of stuff that you might be able to change with scripting in my experience (still not as good as geod's considering things but i'm getting there) but how you change it might depend on what is readable and writable as far as functions (again, i refer to geod's wisdom there)