Chonburi immigration have clarified exactly what is required with regards to TM30 reports and the financial requirements for those applying or renewing a retirement extension.
Speaking to Tommy Dee at Fabulous 103FM, Khun Pichai, who signs all the extensions of stay for foreigners applying at Jomtien immigration answered questions regarding the TM30 form and retirement extensions.
Regarding the TM30 form, foreigners staying in Thailand on an extension of stay are not required to submit a TM30 form each time they stay outside of the province. 
Completing the TM30 form once is enough for those on an extension of stay, Khun Pichai told Fabulous 103FM. Because foreigners on an extension of stay submit a 90 day report, they do not need to submit a TM30 form each time they return from a trip outside the province.
However, you are required to complete a new TM30 if you change address.
For people staying on tourist visas, their host must inform immigration that the foreigner is staying at that address. For hotels or guesthouses this is done when you hand over your passport at check in. 
But if you have a foreign friend or family member staying with you overnight at your house or condo, you are required to notify immigration that the person is staying at your address and are subject to being fined if you don’t.
Regarding retirement extensions, Khun Pichai said that first time applicants must be able to show at least two months of income coming from overseas or traceable to a taxable source in Thailand.
For renewal of retirement extensions, the applicant must be able to show 12 months income from abroad or from  a taxable source in Thailand. The applicant must also be able to show the income transferred into a Thai bank around the same time each month. 
For those using the lump sum method, 800k baht needs to be in the Thai bank account two months before the application date and still be in the bank 90 days later. After this up to 400k can be withdrawn, but the same account must maintain a balance of 400k baht for the remainder of the year before returning to 800k baht two months before the next application.
The report didn’t state what penalties foreigners face in the event the bank balance drops below 400k baht.
You are registered with Thai immigration by us when you check in and
all goverment VAT tax is paid.  Due to Thai immigration policies being
strictly enforced for entry 30 day visa we want to advise our customers that we
continue to report your check in to immigration within the 24 hour limit but if
you should travel overnight in Thailand and then return it is advisable to call us at
087-1400-227 upon your return and inform us so we can report your return to
immigration to the room.  If you visa or stamp changes for any reason also report
this to us. This is for your protection. If you have a guest in the room you also
need to report this to us