I was thinking if I can talk to my neighbor about sharing the cost (I, the landlord, personally provide labor and my neighbor provide material (e.g. fence pickets)).

It's a personal preference.

For instance, said property manager manages maintenance issues, problems that arise during bookings, basically anything that needs a physical person at the property, while I manage the rest?

Personally, I wouldn't offer SubTo or a Wrap, For reasons I've written about fairly extensively. https://www.biggerpockets.com/forums/70/topics/1227199-the-m...However, I would sell on "Lease Option" and that may work for you.

Any recommendations on Houston REI groups that meet in person or virtually?

What I was getting at is that even investing "out of state", let alone out of the country, is more difficult when you don't have any personal connections and even more difficult with your first property.

Personally I wouldn't feel comfortable trying to wholesale a relatives $1M home knowing that I am breaking the law if I cross over into doing anything that can be considered representing them in the transaction, and knowing it will only be marketed to people who buy properties wholesale (typically investors who don't want to pay retail prices), instead of the majority of retail buyers active in the market who are typcially willing to pay more. 

. =) It's literally the most transparent and traceable transaction medium mankind has ever seen lolThe transaction can be traced, but not the person.

they're not magic.are you going to in-person / informal meetups? 

Be prepared to follow up multiple times, using different forms of communication—calls, emails, and if possible, in-person visits to their office.