What do you mean to far? Considering a WC flush tank is considered 4 FU and on an 11/2" line you can run 4 FU 100 FEET I really do not see any problem If you have to, You can always use a 2" diameter pipe then connect the toilet and have an unlimited run in ft..
Should be individually vented
Your problem can be caused by problems other than improper venting. A bad fill valve, a cracked toilet, a partially clogged toilet, or even a clogged drain line. Has this problem just started or has it been as long as you can recall. If it is an old problem it may be vent related... new it is most definitly something else.
Slow or incomplete flushing. Without proper venting, the water is pulling against a vacuum.
Most of the time they are. Depends on how far of course. Usually, the toilet is by the main stack so it only has to go the 12 to 16 inches to get to the drain. The main stack goes through the roof for the vent for the whole house or the bath and laundry. As long as the toilet is getting venting from somewhere, it should still flush.
Yes. If not it will be a wet vent and cause MAJOR problems.
Your vent pipe for that part of the plumbing is either blocked or non-existent. Having to tip the toilet off center slightly is letting air enter into the system, something that should be happening under normal conditions if the vent pipe were working properly. That vent pipe needs to be snaked out and cleaned.
It could be insufficient venting. The water going the drain from the toilet sucks air behind it. There should be a vent going up through the roof which lets air into the drain stack pipe. If it can't get enough air, it can suck air through another drain trap. It could be a design problem, or the vent could be clogged with ice or debris.
No problem as long as the venting is above the flood level rim of each fixture
Definition: Wet vent means a waste pipe that also serves as a vent pipe
To redirect -Ventilate -Venture -Venting
Yes, it is a form of the verb (to vent). But it can be used as a noun (gerund).
Fixture waste can accumulate in vent, eventually clogging it.