Just received mine and have to say I love it. I have always shot with a soft release and really missed it when I picked up the RX100. It never occurred to me that they would have stick ons! Thanks for the heads up Amin.
Is just a single very low "click click" that occurs after focusing each time you half press? If this is what you are hearing (same on mine), it is the aperture stopping down. If you listen closely, it occurs when you release from the half press as well, when the aperture opens again.
3rd party batteries and chargers are available on ebay for around 20 dollars delivered.
DSTE 2PCS 1450mAh NP-BX1 Battery + DC134 Charger for Sony DSC-RX100 Camera NEW | eBay
It doesn't support a wired shutter release or infrared. There are non threaded set ups available, though I haven't tried...