Yes, powerful, as in able to bench 10 tons, basically the strength of 100 men.
Powerful, as in having a Spider-sense, which when used properly, could make him untouchable.
Powerful, as in having 16x the reflexes of a normal human being.
Powerful, as in his agility and wall crawling abilities.
Powerful, as in having webbing which is 5x the strength of steel.
These are the powers Spider-Man started off with, not to mention the ones he now has. If you don't think Spider-Man is a powerful hero, think again. Seeing what happened with Tombstone.....or Fancy Dan.....or Ox just doesn't make sense. There are plenty of ways to take Spider-Man down without watering down his powers just for that moment in time.
No, it's much better to have Brock hate Spider-Man first before Parker. What's the fun with Brock hating Peter? From his perspective, he can beat up Peter anytime he wants. If he hates Spider-Man, there's nothing he can do about it, which builds up even more hate, and it makes it all the more satisfying when he gets the symbiote and can finally stand up to Spider-Man. Who can forget the scene from TAS on the rooftop when Brock first confronts Spider-Man with the symbiote.
http://www.youtube.com/watch?v=jSeqVMuwaig&feature=related
start at 2:25