, the eVisa data is on the system. Your question cannot be answered in this group. But it's your responsibility to get the right stamp and eVisa PDF is only proof you can have and show that you have a valid visa in case.
Basically, your wife under 50 can get on Non-O dependent on you (so-called piggybacking) as the main visa/extension holder.
BUT
If you are applying for single entry Non-O based on retirement/pensioner in UK or inside Thailand, nearly zero chance for her to be able to get Non-O dependent inside Thailand/around Asia.
Generally, you can apply for Non-O dependent for her at the same time as when you apply for Non-OA (in your home country) or Non-OX (in your home country or at the immigration office in Thailand). You may need to contact the embassy or immigration office where you want to apply for details directly.
Q. I'm assuming I just turn up with both passports, copies and relevant form at CW?
-> Bring both passports, fill out the forms, and make the necessary copies to apply.
Maybe not required, but bring the receipt of the new passport issuance.
2 - Can I do both at the same time at the same desk at CW?
-> You can wait until the earliest of your next 90-day report or 1-year extension application. Go to the counter that you apply for your extension at CW.
3 - TM30 - does it automatically transfer from old to new passport? Or does my landlord have to file a new one for the new passport?
-> You ask your landlord to do with your new passport again.
Okay, OP has a VALID Non-OA e-Visa from the consulate in his own country. This Non-OA itself is valid until 28 February 2025. He can enter Thailand until 28 February 2025 without doing anything, including getting a re-entry permit.
During that,
As his current insurance policy is valid until 8 April 2025, he will be stamped in until 8 April 2025 every time he enters Thailand. When he gets a new insurance valid after the current one, he will be stamped in for 365 days or until the new insurance policy expires.
Technically and possibly, he can get a 365-day stamp starting 28 February 2025 for the last time to use this visa.
If he is in Thailand with an entry stamp valid after 28 February 2025 and wants to get out and back to Thailand using the remaining days of this stamp, this is the time he needs to apply for a re-entry permit BEFORE he leaves Thailand.
As you are still on the entry stamp. That stamp cannot be transferred to a new passport. Bring both to apply for a tourism extension. They put the entry information into your new passport first to give you a 30-day tourism extension stamp in the new one.
You had been holding your 1-year extension(s). You entered Thailand on 15 January with a re-entry permit, then applied for a new 1-year extension on 30 January.
Some offices overwrite your 90-day report due date with your 1-year extension application. in most of these cases, you would have a new 90-day receipt or notification with a new due date. At least I understand so.
The best (in the future) is to ask your local office for confirmation of the next 90-day report due when you apply and get a new 1-year extension.