The question is not if this is permitted, but given how immigration are enforcing rules and discretions, if this is realistic. If you have a pristine immigration record, and meet all the requirements on reentry, maybe it will work out. You need to consult a reputable visa advisor and do whatever they advise (a valid visa is not a guarantee of entry even then).

As said by others, if it is strictly an investment, then you can. You must have no operational or directing (you cannot be, for example, the de facto CEO) role.

Additionally, the structure of the business must be genuine, in that, it must not be a nominee (or effectively a nominee) arrangement. You need legal advice to ensure you start and stay legal. There can be profound implications if you are not. You will also need tax advice. I provide none of those services so it’s not indirect marketing! 😂

If you are 100% compliant (with entry requirements) then you will probably not have big issues. However, enforcement can be quite rigorous atm, so allow for the possibility of some questioning. Immigration is enforcing the rules they have mostly ignored for a few years.

Unless there is some very specific rule (doubtful) that having a retirement visa in another country impacts your tax status, then a retirement visa should present no difficulties. However, you would need to comply with the financial and other requirements to obtain and keep the visa.

Tax status is complicated and it most countries it is difficult to extricate yourself from tax residency because it is based on much more than actual residency (here I am talking about citizens primarily).

If you do exceed 180 days in Thailand during a tax year, then you are required to file a tax return. However, this does not necessarily mean you will pay any tax. The rules are complicated and it’s best to get professional advice.

Having a valid retirement visa would definitely prevent some issues with immigration (who are enforcing rules diligently nowadays) but it is not a guarantee of course.