It's hard to see what material your seatpost is made from but I suspect it is aluminium alloy. If it is aluminium electrolysis could have happened between the seatpost and the steel frame. The seatpost may have bonded with the frame. To help break the bond, ammonia could be used to soak the bonded area. You will need to put the seatpost in a bench vice and try to move the frame back and forth to break the bond as well as ease the frame from the seatpost. This may damage the post. Lack of grease between the post and the frame is probably the cause.

Another cause of the stuck seatpost problem may be that the seatpost is the wrong size (a little too big) and the previous owner forced the post into the frame. Again, you might have to put the seatpost into a bench vice and try to move the frame back and forth and some how wiggle the post from the frame. Lubricant may help.

I had a stuck handlebar stem that I worked on every now and then over a period of about half a year before I could get it out of a frame.

As for the pedal axle stuck in the crank arm; I would guess that the axle was assembled without grease on the thread and the thread has begun to strip from the crank arm. If you can get the pedal axle out of the arm you will probably find that the thread is stripped. The thread could be replaced by a 'helicoil'. If the pedals are suitable, you may consider leaving them in the crank arms and ignoring the problem.

Others may have other solutions.