Preparing Project for render farm


i have couple of questions and i appreciate any advice you could give me.
1)i am planing to render a project through a render farm since i’m working on a laptop.I’ve seached online for render farms and came across “rebusfarm .net” and “garagefarm .net” .i have only 40$(USD) budget and rebusfarm prices are so high…so i decided to go with garagefarm…what are your thoughts about their service?..i cannot afford to render twice…
2)how do render farms get my project?do i have to upload necessary project files to cloud and send them the link?..rebesfarms offers a plugin for 3ds max to render it though my laptop on their server…how does that work?
3)i have lot of vray proxies and Xref objects in my projects…some of them unit systems doesn’t match(main project made using feet and xref object project made using meters)…will that cause problems if i send them the project?
4)in the render farms website price calculator they ask for the time per the it the time that specified in the progressive image sampler settings render time(min)?does it include light cache calculation time?i have around 4500 frames and 8min per frame to get to acceptable quality…
5)i have lot of animated cameras and and how do i setup them to render properly?(like CAM 1 from frame 1 to frame 50,CAM 2 from frame 51 to frame 71 so it changes the render camera accordingly)
i know most of these questions might sound stupid to you guys but i’m new to this and i cannot screw this up…any advice you guys can give me would be appreciated…thanks a lot