How often do you need to leave Thailand and what are the 90-day reporting requirements?

You can live your normal life, leaving and coming back here and then for personal matters or job (I'm a regular worker). That's what I do. Never ever have had to leave specifically for the visa in the past almost two years (since I got it).

Everybody is required to do 90 day reporting.

Every 6 months or 1 year, with the extension

Every 180 hours

Stamp is 180days each, you can extend for +180 one time per visit. Yes for 90day reporting, its not visa related its based on how long you stay

You get stamped in for 180 days each visit. At the end of that you can theoretically extend in-country without leaving but this may be difficult. This depends on what you have and your office. Some have done it OK, others may not have what they need (even though what they have was enough to get the visa in the first place).

Really depends, if you have the exact list of what your office wants, you probably can do it. You'll need the activity proof (work or soft power), then the money. Most offices seem to want proof of funds (the 500k) in a bank account (Thai or foreign) for 30 days before the extension, and there may be requirements to separately certify your ownership of the bank account (some banks- easy letter, some people can't get this). Some consulates accepted fintech or investment accounts for the visa, but immigration in country probably won't for an extension. But if you have everything- worth trying I think if you would only be leaving to fulfil the visa otherwise (some people would be travelling anyway). At the end of that 360 days you can't extend again so have to leave at that point anyway.

Many, probably most people avoid doing an in-country extension due to the hassles and just leave every 180 days.

You have to do 90 day reports, presuming you stay longer than 90 days. As most DTV people don't stay longer than 180, it's always the first one on an entry and can't be done online, unfortunately. I think I saw one report of someone succeeding, but most it will be rejected (I tried- was rejected, which I was expecting). If you do extend, you should be able to do the subsequent two online.