Planning to finish basement. Went to Home Depot to get prices and compare materials. Planning on using metal studs, 2 1/2" on concrete perimeter walls and 3 1/2" for the partitions. When looking at the foam insulation, noticed they had 2" thick by 24" wide insulation, and on the label it stated it was for the basement. They didn't have 16" pre cut foam. Is it alright to have 24" on center studs for non load bearing perimeter walls? If so, I also noticed they had both 25 and 20 gauge steel, is it necessary to use 20 guage steel now that the sheet rock will only be supported by 3 beams? And should I use 5/8" rock instead of 1/2" sheetrock? Is there a formula for the spacing, metal guage, and sheetrock thickness?

am installing rec room in basement of a new home. Outside walls were already completed, drywall, electrical, foam insulation. Attempting to add baseboards and can't seem to find any studding going all the way down to the bottom. Suspect shot pieces of 2x4 on cement wall to attach electrical boxes and drywall. My question is: Is there a way I can attach baseboard to the drywall or should I remove bottom of drywall and attach wood to the cement and then baseboard to that?