I think Perriman will surprise people. He came on HOT late last year. He is fast, one thing I want him to improve on was he looks awkward running the football sometimes. Maybe that is just me. I also think Maclin will be a solid addition to this offense, but if I were to put money on it I would say I believe adding Maclin will not make up for the loss of Steve Smith Sr. The team will be fine if Perriman does start contributing more. The woodhead signing as long as he stays healthy will be huge. I think the two ifs will be tight end and o-line like you said.
I think the run game cannot be worse than last year. I think if Wallace, Maclin, and Perriman are able to catch a couple intermediate-long catches a game I think that relieves the offense so much. I don't see the run game going anywhere but up. But on the flip side, I do worry about pass protection. It was already mediocre last season and it doesn't help when you have so many question marks going into the season.
On the flip side, who else is stoked about this defense? It will be a thing of beauty.