So after reading Ters tutorial on map resizing I still have some questions:
1.Is windowed mode a big deal?? I mean is it so important in games? I find myself always playing in fullscreen.

2.Is transparent color in interfaces going to slow down my game considerably??

3.Lets say someone has a smaller screen will Ters proc work? I mean it uses the map size as refference to calculate zoom and view. Now what I want is that when people play my game in different screen the interface preserves its original aspect

here is the tutorial I refer to
http://www.byond.com/forum/?post=1816091

EDIT:
3 is ok it was an anchor mistake I did... everything in my main interface is a child and I forgot to anchor the panes... btw I use auto-anchoring and in my tests I found it to be like 90% eye pleasing there are some cases it breaks ratio when going too small but no one goes that small :D