What is the best HR automation system in the market and why?

You don't. Research the company and hiring manager or would be manager/leader to such things like their needs, recent prior events (& whom else would have been there), near future company goals, products and find a place within that need structure where you would add material value. Then craft what is called a Speculative Application. Get yourself into a position in which travel might be an option as part of your roles.

"What was the best part of you day?" Ideally you could ask in the afternoon .. but it sets a positive intention. I ask this to all my friends + wife everyday when I see them.

Please resist the urge to pull the band-aid. I'm not a fan of keeping a poor performer, but unless this person is a behavioral or "for cause" termination, he deserves some professionalism here. 30-day Performance Plan, make the goals aggressive and stick to it - he can consider that his head start to either buck up or start searching. Remember, your other employees watch how you treat their former colleagues. A quick termination before a holiday is prickish, an aggressive performance plan is taking care of business.

Some of this is stage dependent and all of it is highly dependent on the team above the product manager. The simplest answer of course is to find PM's from companies who have had exemplary success where the Product Manager candidate either led prior success or was exposed to it in a meaningful way. A simple starting point is to ask them to give you examples of conflicting opinions on a feature and how they evaluated the conflicting opinions and made a decision and tracked the success or failure of that decision. AirBnb actually gives PM's homework as part of the interview process where they have to actually present a unique idea (from scratch) to the interviewing team. Happy to talk to you about best process based on your stage and existing team.

If you're using source control, it's easy to track source and control access — or revoke access — if someone leaves the company. Also, your developers should have signed a contract about the project itself that clearly places the source code under your/the client's/the company's control, and if/when they leave, they release all rights to code created under that contract. You can never be 100% sure, but these small steps will at least ensure a legal high ground should anyone steal code. Good luck!