1 - The answer is anywhere from one to 250. Ask a vague question, get a vague (or smart-assed) answer.
2 - Here on IndieTalk we try to maintain high standards (although we don't always succeed), so yes, proper punctuation, capitalization, grammar, spelling, sentence structure, etc.
DO matter. It makes you seem more professional, organized. etc. There are a fair number of professionals on this forum, and they will be reading your posts. Think of it as marketing; do want to be perceived as a sharp and intelligent up-and-comer or just another a sloppy wannabe. Let's face it, your original post was just one run-on sentence.
3 - The term "Indie" is deceiving; it has in recent years come to mean low budget films. Actually, "Indie" is any film with any budget made independent of the studio system. So a film can have a seven or eight figure budget and still be "Indie."
+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+*+
You're looking at the crew situation the wrong way. Start with your budget and shooting script and work backwards from there. You've got to feed your cast and crew well every day, as well as supplying other amenities. You will probably have permit fees, insurance and other such expenses. And you haven't even started on the actual costs of filming yet. You'll need to budget for wardrobe, H/MU, gear rentals and the like. You'll also need to set aside funds for editing, audio post, color grading, CGI/graphics, etc. And let's not forget marketing your film after it'd done.
Once you've gone through all of this you'll know how much you'll have left to pay cast and crew. A decent PSM/Boom-Op with the appropriate gear will probably cost you in the neighborhood of $250/day. For a 20 day shoot that's $5k right there, a little over 5% of your total budget. I don't really know myself, but you'll probably pay that or more for a decent DP with some gear. A very basic audio post will probably set you make a minimum of $10,000.
So you will probably end up with a minimal crew - DP, PSM/BO, scripty, 1st AD, one person to handle wardrobe & H/MU and a couple of strong but smart backs to handle the rest.
Are you paying the cast?
Anyway, that's my advice.
Good Luck!!!!