All-around high temps countermeasures HP Notebook (HELP!)

Good day.

On november 2011 I bought an HP dv7 6189sl. The CPU is an Intel i5 2430M ; GPU is an ATI HD 6770M, 2 GB dedicated ddr5. Since I bought it, I've always struggled in the vain attempt to lower my system temperatures. Day by day they kept growing higher, 'till I got to the point of completely sitting aside my ATI card and using the integrated intel only, so as not to risk melting everything. I've recently moved to Japan. Here my warrancy is useless (I bought the notebook in Italy), and in any case it would had expired in a few months time. Also I know noone who could help me here, so I started checking internet and youtube for valuable tips.

First thing I did (yesterday !) was to completely disassemble my notebook, clean it and and reapply thermal paste. I had never done something like that, but apparently all went fine. I cleaned the old paste and replaced it with Arctic mx-4, cleaned all with alchool and compressed air. Now the temperatures seem to be back to where they were when I bought the notebook: CPU runs 39-40° idle on power saving settings (integrated gpu card). The ATI radeon, tho', is still too hot I believe (has always been). It runs at about 53° IDLE, and rises around 56° just by watching a video. CPU tem rises accordingly. I have to specify that here in Japan temperatures are around 30° now...

SO. After doing all I could in term of cleaning and pasting, I need to tackle the "software" part of the problem, I think. And I confess I feel lost. First thing I'll do is to erase format the notebook with a clean copy of windows 7, so as to get rid of all the preinstalled Hp crap. But I have a couple of HUGE doubts.

1) I've heard the cooling and power settings are prearranged by the HP provided bios, and even changing settings in windows (like fan speed) won't work. Is it true? I found a modded (options unlocked) version of my bios on a big internet community and downloaded it. Do you think it would be wise to install it after format erasing?

2) Which power plan-options do you suggest? Would it be advisable to lower min or max processor state percentage? (I've read someone who claims lowering the max state to 99 percent disables processor turbo boost, which in turn lowers temps, but it that advisable? Won't I lose CPU performance? ALSO, which cooling policy is best? Active or passive?! T_T

3) This question only makes sense if I decide to install the modded Bios. Considering I don't really multitask, and the few high tasking programs I'd like to use don't seem to support it, would it makes sense to disable my processor hyper threading? I've read that by disabling the CPU virtual cores I'd gain in terms of temperature AND of physical cores clock speed. Some people tho say that's not the case :S

4) Now to the most painful and IMPORTANT part. The crappy ati hd 6770M - switchable graphic system, that doesn't allow me to update drivers from the AMD web site. Can anybody suggest a reliable, stable and NOT OVERHEATING ati and ccc driver version? I've tried Leshcat drivers last year, but they rised temps significantly, and that scared me. Also, even by following instructions about how to properly erase ATI drivers before leshcat installation, there always seem to be some kind of problem (esp because of the suggested driver fusion application). Btw, there seem to be a way to install official drivers ONTOP of the HP official package (last release: 2011-11-18 -.-) Is that true?

5) In general, is there anything I can do to lower my gpu temps a bit without physicallly OPENING A HOLE on the bottom of the laptop case, as I've seen some desperate HP customers doing :S ?!

I know I've put a whole bunch of meet on the fire, but there's no other community I think would be able to help me. I don't trust italian forums either, people wondering there mostly know less than I do. I don't want to sound pathetic, but you are my only hope -.-

Thanks in advance for all the help, tips and insight you'll be able to provide me...