Having more capital is better always better. I don't know your trading strategy so I can't give you a recommendation. In general, you should always exit your short strike before expiration. When you exit is based on your trading plan and your risk tolerance. I always weigh the risk of holding onto a position to the additional profit potential. In regard to your example, I don't short options in a raising volatility environment, so I can't answer your question.
urgh did the playbook get this the other way round ? https://www.chittorgarh.com/compare-options-trading-strategies/long-put-vs-bear-put-spread/3/12/ https://www.optionsplaybook.com/option-strategies/long-put-spread/
probably easier to think of the spread as debit or credit and bull or bear. bull you make $ on upside (debit if using call, credit if using puts) bear you make $ downside (debit if using puts, credit if using calls)
Yes. I think they (playbook) mixed up the picture and description in the bull put spread. Also, the picture shown by the OP should be a bear put spread as you correctly point out. https://www.projectfinance.com/long-put-spread/
It is extremely common to exit the position prior to expiration. Most Options are closed prior to expiration. With Interactive Brokers this can be automated as you suggest when entering the position. Depending on your strategy, you may consider SPX or NDX as they are cash settled if you intend to let them expire.
@FrankNbTraderB, I think you better should start with a CashAcct instead of MarginAcct. Then you can forget all the MarginRequirements stuff. The only drawback with a CashAcct is: you can't make any naked shorting, incl. stock shorting.