What?
Are you talking about like what the mushrooms do?
*4zb4 is confused*

I wouldn't recommend teleporting the mother plant away unless you're fighting it and starting to get killed.
Fighting the mother plant (Genetrix Vesana) will significantly boost your skill with whatever weapon you are currently using, which will come in handy later on. Usually I end up with a weapon's skill at about 12 by the time I'm done with her.

Good things to do to help beat her are:
1) Make sure you have all the best armor available equipped on you. Remember that even a broken piece of armor is better than no armor at all - even if it says it has an AR of 0.
2) Throw poison/sulphuric acid bottles at her before the fight to help drain her health. You could also dip ("!" key) your weapon(s) in poison beforehand. I wouldn't recommend dipping anything in acid apart from whips because whips are unbreakable.
3) Kill the smaller plants first. You don't need them nipping at your sides whilst you're fighting the mother plant.
4) Training a bit more on previous levels always helps.
5) Wands. Use wands of fireballs/striking/acid rain to kill her. You could also use wands of lightning but it's hard to predict where the bolts will bounce and as such you'll probably end up hitting yourself in the groin with them. DO NOT use wands of slow on her, as they seem to actually cast haste.
6) Make sure you aren't burdened/stressed or bloated! Both will impair your fighting abilities. If you're burdened simply drop some stuff you don't absolutely need on the floor somewhere before the fight.
7) If all else fails, get a few hits in and then use a wand of teleportation to remove her from the exit tile.

You can also try to polymorph him into something more useful. If you leave him around one too many carnivorous mutant bunny corpses you might end up with a lion following you instead.

And yes, as mentioned above you can also feed him Ommel Bone things. Armors work well, and may be a better use for them since they'll eventually rot and can end up rotting away at the worst of times.

Tips, whited out and shrunken in case you want to find them out for yourself:

1) Don't kick down random locked doors in GC unless you're sure of what's inside. There's a shopkeeper who doesn't take kindly to strangers kicking his doors.
2) Wands work wonders on the Enner Beast. Also detect scroll + "enner beast flesh".
3) Keep all flammable/unstable items in a chest to avoid unintentional detonation/burning.
4) Library exploit. But I'll leave that to you to find.
5) If you're playing LIVAN or IVAN CVS then you should read up on my guide on mustard gas grenades. If you can find it.
6) You can teleport Genetrix Vesana off the UT exit.

That's all for now. Also, always remember: "A Wand of Polymorph hath a thousand uses".

No problem. You might also want to read up on the library exploit if you can find it and aren't adverse to abusing the system

Drop them (d) on the floor of the shop. The shopkeeper will offer you a price for whatever you've dropped.
Also welcome to the forums!

Wand of Polymorph doesn't, and explosions don't do much except break bottles occasionally. Acid is negligible if you get to the items in time.

Key ring would be nice. Like, you "a"pply the keyring to open a chest if it has the correct key rather than an individual one.

2) Yes. I remember a significant difference between the explosions given by a slightly-happy Legifer being somewhat small in comparison to the ones produced if he names you his champion. Also what Al said above.

3) Once you learn how to use them effectively, any god can be greatly helpful. My personal preference is Loricatus and/or Atavus. Loricatus because once he gets to like you he can harden your weapons for free, and shits scrolls of enchant weapon/armor all over you. Atavus mainly because chests are easy to find and offer to him, allowing you to get him happy and receive a arcanite armor (chainmail was it?) early in the game.

4) Any god may replace a limb with one of their materials, as Izzy said above. You might want to pick the right god for this though - I once had a lost limb replaced with one made of mushroom flesh, which was crap. Think I may have prayed to Cleptia or Scabies.

A skeleton key isn't really necessary - any locked chest can be opened with a firm kick/bottle of sulphuric acid/wand of polymorph/exploding mine.
"A wand of polymorph hath a thousand uses"

Not sure a Bag of Holding would be possible as of now. You could of course just give it a ridiculously negative weight, but that would effect your total carried weight rather than the weight of the bag's contents.
Also, would unbalance play


Also I just had an idea: An orb/scroll of scrambling. Does nothing to affect gameplay - all it does is randomly mix the tile graphics and names of all in-game entities around. Think walls having the graphic of a goblin head, and Elpuri looking like 4 tiles of pineapples, and a two-handed sword being a element coloured door. "A door is stridulating here." "You pick up the mustard gas dolphin of agility +2"
Would have to be an extremely rare random spawn, or locked away deep in some dungeon where only forumites/developers would know how to find it.

Yes I believe so. Something to do with their body parts rotting if memory serves.