anyway to grind up stats some?
Depends are you trying to get the ultimate endings or the early endings?
The ultimate ending requires you to basically cheat (Which is why I think everything past a certain point in IVAN is terrible... with everything before that being pretty good).
The Easier endings requires smart thinking and lots of luck.
does the weapon type matter?
Yes, in fact they include an exploit weapon with a secret ability.
The whip never breaks. The only whip that breaks is if you try to fight with belts.
can you cast spells?
Scrolls and Wands only.
guide says to grind in town to talk to certain people to get 'scitalk' which trains up int and/or wisdom (cant remember).
AHH yes, the game breaker. The only way to obtain the ultimate endings and it is completely not given to you by the in game documentation.
You mostly want to do this in order to use the material wishes so you can turn your arms into nearly indestructible constructs of death and things like that.
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I'll pretty much outright say that IVAN is a pretty good roguelike if you aren't going for the ultimate endings. They don't require outside knowledge you couldn't get by playing honestly and earnestly, albeit A LOT because they are still pretty hard.
Going for any ending after that though and you are a total cheat.