1. Both JS and python have supported libraries. Check out https://pypi.org/project/beem/ for python and either hive-js(https://www.npmjs.com/package/@hiveio/hive-js) or dhive(https://www.npmjs.com/package/@hiveio/dhive) for javascript. I personally use hive-js.

2. Its dynamic calculation. I don't know the exact math around it but it depends on certain factors like the size of the transaction, the type of trx and how many other people are doing the trx as of now. Checkout https://beempy.com/resource_costs to get an estimate of the costs.

3. I used to have a bot that placed a sell order on hive-engine every 2-3 minutes. Over 500 HP worth of RC wasn't enough so you'll need a good amount. But refer to question 2 to see more info on RC cost. 1k HP of RC should do it, but you can always add more as needed.

Good luck with your idea.