I'm using the same Office for my Marriage Extension and they always renew the 90 Days Reports regardless how old the previous one is. So just check your Passport and latest Slip.
As far as I know RS Components selling online only all over the world, never heard anything about outlets. But you can get RS Online Thailand also in English language.
Yes,till you leave the Country. My ones is also five years old and Hua Hin Immigration love it to staple it on the last page of my Passport year by year as I take it always out.
I have Pacific Cross Ultima Plan, started in 2019. This old Plan you will not get anymore as replaced by there new "Lifestyle", which is some few thousand THB more expensive. And you have to know that PC become much more expensive when you become 66 years old.
Beside that a lot of Manufacturers advertising this I don't believe that this Filter Mats in the Aircons reducing any PM2.5. Better to buy a Purifier as your 29 microgram are still to high.
What for Health Insurance you are using, looks quite expensive. I'm in the same age, have a coverage of 20 million THB, In-and Outpatient, 40k deductible per year and pay after 20% no claim discount 62.000 THB a year.
Your EV and the BYD App shows you always how many Kilometers more you can drive with your actual SoC, so there is not really a different between ICE and EV.