No, no, no and no.
There isn't much that can, or should be done right now. Rachal is actually still a very young rookie. He came out early after only a year as a starter, and now has only about 10 starts as a pro. He looks like he will be fine but he is still learning the pro game. Rookies have inconsistent games. He just needs time.
Baas is less promising since he has been here for four years and still looks pretty much like the same guy he was. However, he has been injured most of TC and now has an ankle injury. With the simplified blocking scheme now in play, he might be serviceable once he gets healthy.
Moving Baas to center is not an option. They tried that two years ago and it did not work. The murmurings have been that the guy is not the sharpest knife in the drawer and was not effective at recognizing defenses and adjusting blocking schemes - something at which Heitmann excels.
Pashos doesn't need to worry about a position switch at this point. He is still trying to settle in to what the 49ers style of blocking and line play. He needs to stay there.
Depending on what happens Sunday, there MIGHT be some changes after the bye. For now, it will be up to Foerster to work with what he has.