If an known solid QB with experience becomes available that should be the only time we look at making a change there for now. The O-line is priority 1, 2 and 3, then RB.
Siemien is good enough that other areas should be fixed first and Lynch hasn't had chance to show what he's capable of yet either.
I have my doubts about Siemian and Lynch. If Mitch Trubisky is available in the mid first round, they should get him.