yes. I'd keep your flights as they currently are. You've plenty of time to get an STV visa if they do decide to continue with it. If they don't you'll still have time to get a TR visa which will allow you 60 days and then can be extended for a further 30 days within Thailand. You can then always book a ticket to Cambodia/Vietnam/Laos/Malaysia to show you have an onward ticket within your scheduled visa time. You can then then repeat the process when you reenter
that might be possible but you won't be able to extend it past the first three months the way things are currently scheduled so it is of no more benefit than TR visa bit more expensive and with more onerous requirements
The STV is currently scheduled to end in September so won't actually be available to you. If they do decide to continue with it they probably won't announce it until September (that's what they did last year). It was introduced for covid times so there is no guarantee it will be continued
I'm aware of that and if you read the full thread you'll see I've given him full instructions on how to make it himself but what you described was how to cook a cut of pork. Marinating in "spices" for three days is not going to cure a joint of pork.