but the cost is only $75 for 5 years.

Then you can see about the other options and if they make sense based on the airports you fly out and what they have. I would stick with one airline to build miles and status. Maybe look into a CC that can get you higher quicker and potentially get into a club at the airport.

Do direct as much as possible, layovers are just opportunities to be stuck in that location.

See if your employer has any Car Rental connections, mine uses National and I love it as I can bypass the counter and go pick any car I want. Get to drive lots of different cars so that is really cool. And the price is locked in and I get rewards toward free rentals that I use for personal use.

If you end up having to stay in hotel, again pick a brand and stick with it, the perks of that will be a great benefit when you want to do some personal travel. I would choose between Hilton and Marriott. They have so many different brands easy to find a decent hotel and a decent price.

DON'T ever check a bag, always carry on. Don't buy the cheap flight that doesn't allow you to pick your seat and no carry on. Company can pay the higher rate for the next step up.