You are asking help on how to install a product which has nothing got to do with MTA? Be more specific with these 'problems', what and when is exactly happening.
Use /votemap race-mapname to vote for your selected map and /votemap race for vote list of random maps.
Also, use this - CLICK ME batch race map converter by arc_ to convert your race maps into the required format for 1.0.
I play the game at 1680x1050 fine. Maybe 1920x1080 is unsupported or is an uncommon resolution? So the game just limits you to 1024x768 all the time? There isn't any resolution higher than 1024x768 that works?
You mean the streamer? Well the streamer has it's own limit of handling objects in one area and in the whole map. After you reach this limit your FPS will start to drop.
Game-Monitor is slow and it takes a while for it to realise that you actually have a server. You don't always see your server in the internet tab in-game so try any get someone to check for you or else search for your server here
Try other servers and see if they crash too. If it's Valhalla that only crashes then it's some function in MTA they are calling that isn't working. You should upload crash dumps too.
That is the vehicle interpolation being frame rate dependant not being time based, this will be fixed in 1.0.1. As for the crashes 1.0.1 will be much smoother and I'm sure it wont take as long as 1.0 to release.