Can I extend my tourist visa at Cheang Wattana and does my history in Thailand affect this?

i have been on a work permit/visa for the past 15 years and i only recently switched back to tourist one while attending some professional courses and taking a sabbatical.

Because i never had to worry about things while i was on a working visa (yes call me spoilt!), i am a little overwhelmed now.

Is Cheang Wattana the only place i can extend my tourist visa, will those incredible lines apply to my visa type, and what's the earliest i can apply for the extension without loosing days on my 2 months duration.

A bit of a long shot here... does the fact that i paid taxes for 15 years, i own a condo and I have money invested in thailand count for anything at all?

cheers