Offering help is always a tricky call for me, in the situation you mention first I am like you, the guy could feel belittles if it could be perceived he could not set it all up himself
and also as you say one never knows how people will take it if you offer to help, I gues sin most cases people appreciate it, but then theres those who take it in totally the wrong way
Kind of typical that a few people ruin it for everyone else I guess!