hi all! to get to the nitty-gritty!

I've got a print-out of ipd's pdf flush instructions, print-out of 700/900 faq atf flush instructions, and I've rummaged through the archives and found this good piece (among many): http://www.brickboard.com/RWD/index.htm?id=913858 (ken c, I might have some specific questions for you regarding switching to synthetic). however, I still have some nagging questions that I really need answered. I know some may be no-brainers or silly, but this is one of my biggest diy job, big only because I've never done it before and have always viewed it as a "you need to know what you are doing" sort of job, so I really want to know everything before I take on this job. okay, this is what I'm gonna do and my questions:

1. is it best to flush when atf is at operating temperature or when stone cold? I don't remember reading about this anywhere, but ipd did say drive car to get to operating temp, let cool for 30 minutes so as not to have to deal with scalding fluid, then flush. (I'm thinking more of flushing fluid after a good drive to get all the debris floating and flushed out.)

2. I plan to drain the pan first, so I expect around 3-4qts out. now here is the nagging question: I plan to switch to synthetic, so will I need to pour in 3-4qts synthetic into the pan, or will plain dino atf do before I begin flushing?

3. I'm not too clear on this, and it's the part I'm nervous about. I have an aftermarket all-metal radiator. to unscrew the top/upper cooler line, do I place the flare wrench on that 1-inch long nut/bolt? what is this I hear about using another wrench to counter loosening the cooler line? do I need to be super gentle with this step, so as not to break anything at this connection point or cause any leaks of one fluid into another?

4. is synthetic backward compatible with dexron II (think that's what my car uses), faq says mobil-1 meets dexron III specs. even though I will be doing a flush of the dino atf, there might still be some residual dino atf (dexron II or III) that may mix with the synthetic. is this something to be concerned about?

5. since I will be switching to synthetic for the first time, will I need to make a follow-up flush with synthetic again to rid tranny of all regular dino atf?

6. this is probably a no-brainer, but it is one of the nagging questions. as fluid is pumped out via the return hole on the radiator, do I need some helper to pour atf into the pan simultaneously to immediately compensate for the loss...OR do I do one at a time: run engine for 30 seconds, 2qts come out, stop engine, and THEN pour 2 qts in? this part of removing and adding fluid was never clear to me. in fact, I think ipd says pour in atf AS atf is coming out, sounds like a hassle. I might be doing this alone.

7. I still don't know what the difference between dexron II and III is. are they compatible?

sorry for these long post and lots of questions. I hope I've made my questions clear and coherent because it's kinda hard asking intelligent questions when you don't have a big technical or a mechanic's vocabulary. thanks in advance.

btw, is it worth switching to full synthetic? what brand synthetic is recommended? mobil-1?