It's only too close if you wanted a bigger screen than what the distance may comfortably allow. (more viewers).
by having a smaller screen, you won't necessitate as many lumens from the PJ.
OTOH, you will have, um, a smaller screen.
edit: thinking about this... I suppose the closer the rows are to the screen, the greater the difference in viewing angle between the two rows (assuming constant distance b/w two rows of roughly 6 ft).
Like I ALWAYS ALWAYS ALWAYS ALWAYS say...
how about firing the pic on the wall, and go from there?
All of your questions could be answered. After all, its hard to predict your personal preference, from our point of view. You will in fact find that its hard to predict even just for yourself when it comes to these matters.