@gxsaurav....i use TIFF for later Photoshop works once the project is done in max, for rendering as i mentioned early amd as you rightly said TAGA ...
and render in 320/240 for home use, use 640 for professional use ...640 could do away in homes use...but i will not recomend that ... its a waist of rendering time..and u can see the effect in 320 ...which is just needed for home.
dont go for any thing higher its not needed...unless you are going to broadcast in to the local movie theater.....
you can go for inteo video codec 5.10 too... or cine pack.
and regarding the TIFF thing i think it speeds up the network rendering time...if you are rendering using the home network. it did for me though ..or it may be my personal exp...or machine fooled me...

, i dont believe comp. these days
and for the other part....DO NOT fit the video full screen....not at all recomended...why do u want to mess up your work ...rather put your presentation in such a manner that the 3rd person can preview it in a media player or so...which opens in a new window.....that will be better, you can also open the video in a diff page or window...keeping the 320 size....or 640 if u like it....but i usually prefer 320...the person on the other side only looks at the animation , and not the picture quality , if he needs quality then he will be looking at the stills,