Bear with me as I am a newbie

I hate the way clasps on chains often migrate round to the front if the balance isn't right and am looking to make pieces with chains that can't spin.

To do this i want to use a thin ball/bead chain and attach fastenings to it, like the maker has done in this necklace: (i can't post the url but it's 'silver and gold vermeil charm necklace' by Will Bishop)

There is a lobster clasp at the back not shown in the picture.

It seems i need to be able to solder the back clasp and front fastenings with jump rings directly onto the chain to make it secure. I am a bit daunted by this as the most i've done is solder jump rings shut.

My questions are:

what order do you do this in? solder the fastening onto the chain, then close the jump rings?
will a small torch (the mini butane ones) be sufficient, if the piece is not too large?
is the solder going to want to flow along the chain and stop the balls from flexing?
what fastenings do you even use for this?

help with any of these questions would be much appreciated, or a work around if this is likely to be too tricky for a beginner. I'm okay at soldering but no experience of soldering with chains.