There are 2 types of LORs-
Academic - given by your professor or project head
Professional - given by your team leader, manager, or mentor

Here are a few people you can ask for a reco from-
Co-founder
Mentor
Magazine editors who have written about your company
Your client/s

No, it will not.
But make sure you use the college/company letterhead to signify your recommender's authority.

Your recommender will have to upload the LOR separately for each university.
Professors and bosses are usually very busy, and won't find the time to change the university name every time they upload your LOR.
So, it's not advisable to name the institute in your letter.

Wait until the term starts...
Universities usually don't share this information because you might help a friend apply for the program in the same term

Then, email them...tell them you wish to improve and apply again
I don't guarantee you'll get a reply, but...no harm in asking, right?

Holding an extra I 20 basically means holding another students seat
I would suggest you pick one college as soon as possible, and tell the other you won't be joining

Hi Adrika,
You can only apply once in the same term
However, you can re-apply for the next term or next year if you wish
But remember, when you re-apply, your profile has to have evolved considerably

This happens when the admission committee thinks you might be better at another course...or when the seats are filled up for the course you applied to
I suggest you consider the program you've been accepted in...see if you like it...curriculum, faculty, and opportunity-wise
If not, you can always email them and say you want to be considered for the program you applied to, instead

Following are the assets that are acceptable for VISA interviews-
Income - Salary slip
Savings - Passbook or bank statement
Fixed/Recurring Deposits - Certificates
PPF / PF / GPF / EPF - Letter from the company
Bonds, NSC, KVP, etc - supporting originals
Mutual funds, shares, stocks, and other investments in the market - DMAT or NSDL statements
Insurance - Surrender Value Certificate
Scholarships - Scholarship Letter
Loan - Loan Sanctioned Letter
Gold - Gold Evaluation Certificate by any jeweler

Hi Rajesh,
It's important that you decide which university you want to go to and book your VISA appointment by the time May ends