there really isn't glitch city but if you put in a specific cheat of something, maybe you might come across glitch city.
WARNING: glitch city may not have a Pokemon center due to the glitches...
cinabar island
You can find this information on bulbapedia, but some well known ones are Glitch City, Mew Glitch, Missingno. Glitch, and there are limitless glitch pokemon.
In at least red and blue, yes.
Yes, it is north of Ilex Forest or south of Goldenrod City.
There is no tower, not even a glitch tower, in Pewter City.
The legimitate way is to download the GS Ball from a Nintendo Promotion Event and send it to Gold from Crystal, then place it in the shrine in Ilex Forest. There is also a glitch found by Paco_81 in Glitch City Laboratories. Check Glitch City for the glitch.
No, there isn't a glitch to get all the Pokemon in the games.
Q is only in RBY. Glitch Pokemon do not stay from generation to generation; the only glitch Pokemon you can get in RSE are Bad Eggs and ?.
Your question is incredibly vague, I can only say three things about it, and those are this: 1. Yes, glitch city exists. 2. No there is no serious side effects of going there. 3. To go there, go to this site: http://www.ocf.berkeley.edu/~jdonald/pokemon/glitchcity.html
yes, invisible shining bulbasuar, then again its a glitch Pokemon itself.
There is a cloning glitch in the battle frontier.
You don't get to glitch city. It's not real