There is an old thread (NSE Alpha Membership) in which Nithin answered questions related to NSE Alpha membership. It still remains relevant for many of your questions. Quoting directly from that thread where relevant
There is a Compliance Calendar which lists out annual, half yearly, quarterly, daily compliance requirements for the members of the exchange
As far as I can find, that initial deposit ( aka Interest Free Security Deposit (IFSD) ) is only returned when you surrender the membership and not before that. But as suggested above, better to ask NSE directly
As that thread is old, that cost might be out of date. In recent Kite Dev forum threads, the cost for co-location (mainly used for HFT) is mentioned as around 18L/annum
Couldn’t find any agency/company advertising such services on the internet. But I think full-service law firms specializing in this area would be able to help
Many of the one-time and recurring costs have been mentioned above. For exchange specific one-time & annual costs, refer to this
Presently, the Exchanges provide a snapshot of the 5 best bid and ask quotes free of cost to all the trading members. This snapshot is updated almost every second. Trading members and their constituent clients place orders based on the best bid and ask quotes displayed in the snapshot.
This is something a CA or a lawyer specializing in this area would be better able to guide/help you with
Lastly, I do want to share a tweet that I came across. For more context, this was a conversation between a trader (who posts daily P/Ls running into 6-7 figures consistently) and a person (who asked if NSE Alpha membership would be an alternative for them). From what I can guess, that trader would be managing capital in the range of 8-9 figures but even they are frank enough to say that NSE Alpha membership isn’t for them due to various regulatory/compliance/capital/infra burden that Alpha brings with it. Maybe Alpha membership doesn’t make sense until one is managing capital in the range of 9-10 figures. This is also what Nithin remarked in the original thread
I don’t have complete knowledge about this, the best way would be to ask NSE directly about it. Their Trading Member manual might also be helpful.
But I have heard Nithin remark that it takes around 2 years to get a broking license in an interview (At 30:20). The admission process diagram on the NSE website demonstrates the various steps that need to be followed before becoming a trading member.