In final fantasy VII, even if you dont do many sidequests, as long as you dont run from battles, you wont be underlevelled and the game wont be piss easy either.

depending on materia set ups you can either be experienced or inexperienced and enjoy the game either way because basic understandings all you need for fun, and advanced stuff makes you feel pretty cool too.

KoTR pretty much ruins the main story and omnislash too, to some extent. its good to get them on a second playthrough or by leaving northern crater after proving yourself once. because it feels good beating the game without things that aren't neccasary.

Its always a great quality in a game if your never actually forced to level grind or get secrets. but you of course may at your own leisure.