My experience with Thai embassies in Oz, they each have different policies. You may want to double check your findings at one embassy with a different embassy. I found the Brisbane embassy easiest, Melbourne a close second.
What Stuart said. I frequently go between Phuket and Pattaya, I will do my TM30 in one place and extend another. However, to extend you must have yout TM30 done there as well. So you can do your TM30 at the location where you wish to extend.
I was wondering about that, if they get the visa in their home country, it's 3 months visa that has to be extend 1 year? Do they not have to show funds when the extend, as they would if the got the visa locally?
In other words, you have a Thai friend who is willing to pose as your wife for visa purposes. However, her time is limited so you need to know when she should be there?
Sorry for your loss. In the US we lost a loved one. The people doing the cremation told us the paperwork is a real hassle if you want to spread the ashes anywhere. They suggested it maybe easier just to do the thing, skipping the paperwork. My apologies if my suggestion is offensive (travel with the ashes in suite case).
I have a friend who uses retirement visa. He tells me there is difference in insurance requirements for retirement visa attained abroad vs those attained locally. You may want to come here to get your retirement visa... But I don't have first hand information. I know the more I deal with immigration the more I like using agents.