>>2937734
>anglestops
definitely worth replacing, if all your lines are copper they're likely compression stops and this would be a relatively easy one day job to do all at once
you can unscrew the old ones from the old ferrel+nut and reuse on the new stops
each one should just take a couple minutes
i just did this for someone at 60$/ea x19, 3 hour job
i highly recommend because nonfunctioning stops is just a pain and it's super cheap to DIY
if they are sweat on stops (super uncommon), you can torch them off and replace with a compression stop after sanding well

as for the kitchen faucet, you can likely remove the handle with an allen key to get to the cartridge and blow it out or replace
modern faucets have flow restrictors build into where the the pull hose screws together, which can gunk up and they can be popped out
it might also have an aerator with a filter(flow restrictor) that can be cleaned
all depends on the faucet

as for the sink, i'd chill with the 2x4 but you can youtube the process. essentially you drop it, grind off old epoxy, apply new, slide in 2x4, install mount arms for extra support

went to a customers house and they had a sink supported by a soccer ball once