If someone has end stage renal failure. Wouldn't they have severe swelling all over from fluid accumulation?

Possibly. It depends if there is still urine output or not. Some people maintain good urine volume even if they are on dialysis and in that case there is an outlet for fluid excess to leave the body. In the absence of urine output only dialysis can remove the extra fluid so a restriction of intake is mandatory.
I agree. I agree with dr. Moses and wanted to add that people with advanced kidney disease may have good urine output, but urine "quality" is more important than quantity. Normal kidneys can filter much more blood per minute than sick ones, even though the end product (urine) may have the same volume as someone with sick kidneys that have filtered much less blood.
Depends. Most likely if developed acutely (suddenly). If slowly progressed to end-stage (i.e. From chronic kidney disease) then may not as may still be making some urine and/or they may be on a strict renal diet and fluid restriction, and so on. They might even be on some type of renal replacement therapy (like hemodialysis) that controls the fluid accumulation.