You definitely need to be in MLS, whether you use a full service agent or a flat-fee broker depends on how comfortable you are with the process of a real estate transaction.

This year I signed up for sessions there like underwriting multifamily and cashflowing multi family in high rate environments and I'm excited to hear what they have to say, plus it's in person so lots of good networking to learn from others.

Not saying its for everyone, but take comfort in the fact that everyone who now owns investment properties once had no experience. 

A family with young children is unlikely to be comfortable having a stranger living in their backyard. 3.)

I would suggest to start researching Idealista, however even before that thinking yourself where you feel comfortable to invest and what your investment plan would be.

I live and invest in a classic "cash flow markets" (which has seen 8 years of steady appreciation and is hyper competitive and has very little inventory), and I would not feel comfortable to promise you quick and easy cash flow, certainly not within the time limitations of a 1031. 

I believe this is correct - doable but very challenging to qualify STR with conventional in a high-rate environment like we've been in.Sharing this article published last year on STR Loans Options Pros/Cons, etc if it helps!

I would put the student loan on an automatic minimum payment plus some comfortable, but not too large, additional principal payment (if available) per month, then forget about it.

look at your experience level with reality in mind.I would want to feel very comfortable about those things before spending time on deals and money when i had no real capacity to transact no matter who the lender was.

You will do better door knocking when you feel comfortable, and when you feel comfortable the people in front of you will feel more comfortable and they can tell (but we should also not feel like you are dressing for your living room either), and so dress how you would want to dress, in a way that is clean, professional, but more casual in clothes that fit well and are not uncomfortable to tight or too big--  otherwise you will feel it as soon as you knock on the door.