It is up to servers where their admins are - it's not in our control who or where server admins are.
Making all Spanish players admins might have some unwanted repercussions, but is generally a sound idea.
If you set it, it would override any built-in MTA functionality for switching the syncer.
It seems there's a fairly clear case for having a more 'raw' way to send packets of data to the server - or maybe looking at optimizing the existing element data/event stuff.
You can manually iterate over the element tree, if you're specific enough this shouldn't be too slow.
Use getElementChildren on the root node for the resource, combined with getElementType. See https://wiki.multitheftauto.com/wiki/Ser ... _functions
You should save the location of things using map files - that's what they're designed for and will probably do what you want in a couple of lines.
See saveMapData which will save anything you have loaded in-game into a map file (or just part of what you have loaded).
Well you don't want to give them exactly the same controls you're pressing, you want to give them the controls you were pressing some time ago. This won't work well when you're accelerating or decelerating though.
Vehicle AI shouldn't be that hard, it's just a matter of simulating the presses of the buttons to get the vehicle to follow a path. You can export the paths from GTA and import them in an MTA friendly format - that will let you defined your own paths if you want to use custom maps. Competitive driving - evasion, collision avoidance etc is more challenging though.
Why not use account data? Learning SQL and Lua (and programming) all not going to make your life easy. Account data should do what you want.
https://wiki.multitheftauto.com/wiki/SetAccountData
No, you should either be in the list or not in the list.
Port forwarding is almost certainly your problem, check http://portforward.com/ and check that your game port (probably 22003) and the query port (the game port +123) are open. Try getting people to connect by telling them your IP address (http://www.whatismyip.com) - if that doesn't work you've got a port forwarding problem.
Lua is certainly a more widely-accepted language and has been used in many games. Learning Lua is certainly more likely to be useful to you long-term than PAWN, and might even get you a job. It's also much more dynamic - which tends to make it faster and more fun to use, the downside being that you're more likely to make silly mistakes that the compiler can't catch (as with any dynamic language).