Hi Smileboy- first of all let me welcome you !

Congrats on the feelings you are experiencing!!

"1) I have been exposed to quite a few different techniques to amp up arousal and to help with ejaculations control - I have been using them a bit to date and now wonder which of them will conflict with the "protocol"
For example should PC clenches done on the day of a practice session be avoided to give the body/ mind space? - I do some I cong exercises - and they do increase energy circulation in my body (but not necessarily sexual) the pelvic rocking one often causes a gentle erotic tingle - Is it best to avoid that or all the Qi cong on practice day as well.... etc

Regarding the PC squeezing/clenching - yes I feel it should be avoided when you are doind KS practice...Not so much for the mind/body space but as this I think creates 'tension' rather than the relaxation and awareness of body that KS awakens.

Yes- IMHO avoid combining any other form of energy arousal like Qi cong WHEN you are doing your KS practice.
The whole focus of key sound multiple trigger orgasm protocol is to allow your body a chance to awaken it's energy/sexual energy awareness. Those first subtle energy/echo effects may not particularly 'feel' sexual in the beginning- but do note any new feelings/sensations that you DO feel occurs.

2) a pillow under my back doesn't seem that comfortable - should I persist and see if I get used to it? Like wise - pushing my stomach OUT on the KS does not yet seem natural although I think I am making the KS correctly.... should I persist and try to get use to it...."

If the pillow makes you uncomfortable THEN by all means remove it. It is only a suggestion offered. it is all about finding what is MOST comfortable for you. Me i lay on a folded quilt on the floor (more cushion for the hips and shoudlers and also gives the sensation of floating on clouds). About the pushing the stomach OUT - I don't think that is what mine does - but then I dont focus TOO much on that part-- just making sure my chest and neck are in the correct placement for the KS - to make the chest 'rumble' with the KS- the rest just seemed to come naturally for me.
When i make the KS - my stomach seems to naturally 'deflate' as i exhale the KS out.
I hope this helps -

I wish you ALL THE BEST on your journey!!

With all my loving light shining,

Laly