Pat,
To me the real test of how professional a sheetrocker is can be determined by a nice smooth finish. Smooth is the hardest of all finishes. Think of it this way... when something is smooth any break in that is noticeable. If smooth is what you want get out your phone book and get some bids or call your friends for suggestions on tradesmen.
I have rentals and do a lot of work myself. I do a finish that is a modified "knock down". This hides my weaknesses in finishing. The sheetrock is hung well. Taping and mudding takes some time to get a good technique but can be done. But then all the sheetrock should have a skim coat and then be sanded and another coat, etc. This is what gives the smooth nice look you want. In my rentals I don't have the time, or the skill, to do smooth; so I usually have a slight texture.
I am pleased with my skills and the jobs I have done over the last thirty years, but to be truthful, I usually don't need smooth.
IF you decide to try it... you didn't say how high your ceilings are... mine are 9.5'. So I rent a sheetrock lifter. It really helps me. I use it on ceilings and have used it on some walls. To cut down on seams, I'd layout the job with the largest sheets of sheetrock that will work. So instead of 4 x 8, I'd get 4 x 12, etc. Every seam that doesn't have to be there is one more smooth place on the wall that doesn't need mudding. You didn't say anything about your ceiling joists or studs, but if they are out of square/alignment that can also affect the look you seek. Other tools are not too expensive: trowels, utility knife, sheetrock square/straight edge, electric drill to screw in screws, chalkline for marking studs, keyhole saw to cut out areas around outlets, tape measure, and if you decide to texture there are hoppers for spraying mud onto the walls to give texture.
And lastly the blistering should be investigated. That is not normal. Rust would indicate to me moisture. Perhaps you have a leak in the roof? Is there a floor above this room? Perhaps plumbing... water is sneaky and can travel a long way from where the problem is. I once had ants in a rental. The next made the ceiling soft and it all had to be redone. Animals, like squirrels, mice, birds, etc. can also cause moisture that can cause problems on sheetrock.
If your house is empty, be sure to keep it warm now that we are entering the colder months. It will help to keep your materials dry and not damp-ish and will protect the unused home from issues that can arise from lack of use. One other thing... as an older woman, I don't have the strength that many a young fella has, so I opt for "slight of hand tricks", if you will. I do things differently than some may expect. I have hung sheetrock horizontally instead of upright. If the ceiling is eight feet or less you have just the ceiling and center seam on each wall. And the seam is right where you can work it. Most furniture is three or four feet high and when in the room and next to the wall you rarely notice the seam. So my walls look quite nice. Besides if you're looking for seams you are probably looking vertically and you rarely see mine running that direction. Good luck. ____________
KaCe