I actually wanted to shorten the jacket for 1 cm.. The shoulders are to be fitted, the fillings need to be so to say fixed/ cut. I have problematic legs, my quads are enormous and this last month I am even skipping leg days in the gym but.. I want to tighten them a bit starting from below the behind to the knees.
Do not shorten the jacket, it's already quite a bit short, in my opinion. I'll not comment on the shoulder line as the tailor's style is very far from my taste, but bringing them in a bit would suit you better, in my opinion. Btw, the sleeve seems to need some rotating, but those pictures are not very good.
Regarding the trousers, tightening them will not resolve the problem, as your diagnosis is wrong, in my opinion, they suffer from long back balance and no leg opening in this world will solve this problem.
Did your tailor mention some of those alterations?