I don't know why you would say that. Thailand allows (or at least, tolerates) dual citizenship. For travel anywhere within the 10 member ASEAN region, you couldn't do better than with a Thai passport.
Yes, for Malaysia and Singapore, many western passports receive 90 days rather than the 30 you receive on a Thai passport, but unless you need that much time in those countries, then a Thai passport is superior because you won't need a visa for Laos, Vietnam or Indonesia and stay 30 days.
You can use land border crossings with neighboring countries that only allow local citizens across with just an ID card and border pass, including borders such as Mae Sai and Mae Sot, which are currently open to Thais, but closed to foreigners.
For Cambodia, you can stay for 14 days. For the Philippines it's 30 days. Brunei is visa-free too. Myanmar is visa free for 14 days if flying in. Land border entries only require an ID card but with restrictions on how far you can travel.
China is visa-free for 30 days. Russia is visa-exempt for 30 days.
With a Thai ID card/passport, you don't need to pay farang fees while visiting tourist sites.
You can start a business and work anywhere.
If I was afforded the privilege of holding a Thai passport, especially for permanent residence in the Kingdom, then obviously I would take it over a spousal visa that offers few rights or privileges.
In theory, foreign males married to Thais are eligible to apply for naturalization after only 3 years of marriage too, but there are a number of other requirements to fulfill as well:
1. Must be on a non-B, non-O or other acceptable extension of stay (tourist visas, DTV, LTR, privilege, retirement and other "tourist type" visas that don't allow the holder to work or otherwise have no pathway to permanent residency aren't eligible). The LTR allows you to work in Thailand under specific conditions, but offers no pathway to residency. An analogy I make is that it's a "rich man's DTV" but still in effect, kinda like a long stay business/tourist visa combined into one.
2. Must hold a Thai work permit throughout the entire time, no exceptions
3. Must have an unbroken extension of stay for 3 consecutive years
4. Must be earning 40,000 Baht per month, every month (80,000 if not married to a Thai)
5. Proof of tax paid for the entire period prior to application
6. Charity work highly advisable
7. Bonus points if applicant is aged roughly between 40 and 50
8. No criminal record
9. Bonus if applicant is fluent in Thai, but this isn't a requirement if you're married to a Thai. It's required if you're not married to a Thai national
It usually takes several years after applying, before an applicant is granted Thai citizenship.
Which is what I would do, but a one way ticket can be problematic. Airlines might not issue you a boarding pass. Vietnam generally demands proof of outbound travel if arriving for tourism purposes.
I don't think anyone will be attending the consulate in person anymore. They will probably just ask for additional documents, which may extend the processing time.
Show me a spouse visa that is valid for 5 years with a stay limit of 180 days per entry. Vietnam has one for foreigners married to it's nationals, but Thailand has long been more xenophobic and less willing to accommodate foreigners married to Thais. That is, unless you're a woman married to a Thai, then it's a different story. Until relatively recently, they could immediately qualify for naturalization but these days, a few years of marriage is first required.
Don't use autofill. It often doesn't work. While I have so far never dealt with the Thai e-visa system, I deal with the Cambodian and Vietnamese ones a lot.
On the Cambodian one I did recently (for a business e-visa) I allowed the system to do autofill, then I had to go back and manually fill in all the fields. In the end, they didn't have a copy of my passport in the system when I went to check my application later.
I added one, but this reset the processing time, in the sense that the system told me I now had to select an entry date 3 days later. I probably shouldn't have touched it.
Fortunately, just 5 hours later my visa was issued.
Now of course, the Thai e-visa system may be different, but the point of my story is to be very careful about how you fill out these forms and don't go back and make amendments after submission unless you're able to contact someone about it or the system actually allows you to. Some don't.
Precisely. It doesn't even register to them that you may be living in Thailand.
At mainland European airports on the other hand, especially when departing from Switzerland (regardless of whether its on THAI or Swiss) check-in staff don't check for onwards tickets or visas. They just issue you with a boarding pass.
Australia used to be like the UK, but is now less strict. America is quite strict, similar to the UK.
Don't worry about the guarantor in Laos. Just put someone in Thailand or back home. I know people in Laos, but they can't expect that to apply to your average foreigner just passing through town on a visa trip.