I'd try removing the door and see if you can refit the seal into the groove on the door, maybe a little super glue to hold it in place. If it is, in fact, torn or split from th groove in the door, then you'll need to replace the whole seal. If you just cut the loose end off, the door will probably leak at that point.
Sure you can cut it off so it's not bothering you.
When you do, you'll only have a partial seal left, though, and whatever amount of water that's currently dripping under the door will continue to do so.
If you'd like to stop the drips/leaks, then you'll need to replace the entire seal. If you were to try to replace just the torn off bit, you'd still have ...
So although I agree with Jason's answer that there is no technical way to fix this the "Correct" way without tearing it out and starting again, I decided to try my own permanent solution to attempt to avoid a costly repair.
What I ended up doing is going out and getting two packs of Loctite's marine epoxy. This is supposed to bond to PVC, concrete ...
it was installed wrong, there's no real correct way to fix this other than starting again and using the correct fitting.
The correct way is to use the pipe fitting that matches the shower base,
you may be able to do from below or it may require disassebling the
shower floor and walls in addition to cuttihg a hole in ceiling of the room below.
Next best is ...
FIXED! The problem was these little buggers inside the shark bites. Don’t know why the handy man use shark bite instead of soldering, but those little plastic bits were restricting the flow enough to shoot everything right up to the shower. Removed them, replaced everything, now the tub works as it should. Holy smokes!
There's a very good chance it's caused by a blockage from a lower unit. You could try running a snake down your shower drain to see if you could clear the obstruction. Other than that, since it's a rental let the landlord know about this as other units might be affected. He should be the one to call the professional, not you.
In your first picture, you are looking at a ball-swivel assembly that is part of the previous shower head that was attached.
If you take a wrench to the flat spots on the swivel-ball base (clearly seen in your first picture) and unscrew the swivel-ball, that entire assembly will come off and you will be left with the standard 1/2" male NPT shower arm ...
Seeing air bubbles usually indicates a problem with the vent stack that comes out your roof. The vent stack serves as an escape route for any air in the pipe to go when water and poo poo are put into the system. If it's not built correctly, or clogged, the air has to go somewhere, so it eventually makes its way up your drain. If you were the homeowner, I'...
With such small tiles, you will want to bond those completely to a backer board. So, your options would be as follows:
Shim out the studs so that you can install a backer board down to an
1/8 inch above the tub rim. They make drywall shims that are commonly
available at hardware stores for this purpose.
You might be able to use a foam backer board, such as ...