Re: leveling a toilet
The plane of the toilet won't affect it's flushing ability, only it's comfort to the user. Rather than making shims, you'd be better off buying nylon toilet shims that won't crush or rot if exposed to moisture. Also, if you try to level the toilet, you'll need to replace the wax seal underneath it.
1 - Purchase new wax seal and hold down bolts. I prefer the seals with a neck, I think they work better, though you can use a seal without the neck as well.
2 - Turn off water supply to toilet. Flush then plunge as much of the excess water out of the bowl. Disconnect water supply.
3 - Remove the hold down nuts on either side of the toilet.
4 - Lift toilet and set it on a garbage bag in the tub/shower. Lay the toilet back so you can clean off the base of the toilet where the new ring will reside. The toilet has to be clean and dry for the new seal to stick.
5 - Clean the toilet flange on the floor. If the toilet bolts are in good condition and you can get the hold down nuts back on, you can reuse them. If not or you're unsure, replace them with the new set.
6 - Set the toilet without the new seal and level it with the shims. Place the shims in at least 6 even clock positions around the toilet. Tape the shims to the floor to hold them in place until the toilet is permanently set.
7 - Remove the toilet being careful not to disturb the shims. Install the new wax seal and carefully reset the toilet, applying even downward pressure with a slight wiggle to settle the toilet into the wax seal and onto the shims.
8 - remove the shims one at a time and trim to be flush with edge of toilet.
9 - Tighten the hold down nuts until they are just snug plus about 1/2 a turn more. Gently wiggle the toilet and continue to tighten the nuts a little at a time until the toilet ceases to wiggle.
10 - Reconnect the water supply and turn it on. Flush toilet, check for leaks
11 - You can caulk around the base of the toilet if you wish, but leave a gap in the caulk around the back. Caulking is optional, not a necessity.
While the toilet is off, you may want to flip it upside down and backflush it with a garden hose or toilet auger to make sure there is nothing lodged in the trap.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!