If the shop changed the chain and you are now experiencing problems that you were not having before the work was done, the best thing to do is to go back and ask them why this is. If they want you to change more parts at an additional charge, be firm and refuse, politely. Limit screws that you have circled in your photo should be set and forget, I cannot remember having touched limit screws on a front derailleur on any of my bikes unless I changed a crankset (or the derailleur itself)