Everyone has to live trough their own experiences, also regarding the foreigner /Thai relationship. Don't matter if 50 guys say "my Thai wife is genuine" or 50 other guys say "my Thai wife was a scammer" as there is nothing carved in stone. Best way is an open mind, and take it from there. You never win in any lottery if you don't buy a ticket. Don't spend more then you can afford to loose is a good way of thinking about it.
So as a foreigner you can buy a house and own it, but you can not buy and own the land the house is on. So if you buy/build a house on her land, you can make an agreement with your "wife" to lease the land for 30 years, with an option on 30 years more just in case you become the world's oldest man 😁 So a good indication is that if your "wife" agrees to the 30 year leasing with no hassle, you can trust her intentions 😊
Yeah with a Schengen visa you can travel all EU countries (except Cyprus) Switzerland, Norway and Island are also Schengen countries. For UK you need to apply for separate visa.
just that there is where you get sorted re entry. There are multiple check points for immigration (4 i think) so if you go trough in the end of airport, you have to walk back to get re entry sorted. If so just make sure you have some spare time.
Just go and get it sorted. If question about your TM 30 just explain the issue. Probably they have you registered on computer, so no fuzz. Worst case scenario is a 2000 Baht fine