Difficulty In choosing sprokets

so basically the last thing i want to do is sell the bike as i actually enjoy it, if i continue to ride it will the arm opain go away or just get worse?
Also is the 4cm really that much of a big deal could i just raise the saddle and raise the stem as high as possible?

Your urine and faeces will slowly build up until it runs out of spare body space eventually causing your head to explode in a shower, some say, more horrible for those near you than yourself.