Velbus RGB , homecenter... Questions

Dear velbus users,

I’ve made my homework about Velbus. I do think it is a nice system price/quality/features.
The price can furthemore be pressed down by using k8064 dimmers.

I currently have (old type) low voltage controlled telerupters.
I would like to keep my future domotic automation project simple, separated in modules.
That is : central heating with brand specific modulating thermostat / central alarm / home cinema / … all seperatly, but interfaced with some binary VELBUS in/outs and manual IR remote.
(switch off lights when arming alarm, place heating in night mode, etc)

I believe Velbus is perfect for this.

I would like to ask advice about some things :

Pïty that RGB is only half supported. DMX would have been nice.
The way i interpret it know. It seems like we have to use 4 buttons for a RGB armature.
And maybe one more or 4 more for the next one. (1 if you will use same colors)
That is 3 buttons for color mix, 1 for easy switch on/off.
No auto color mix or overall dimming.
Anyone found a better way for this ?

Homecenter looks like all i need and sharp designed.
Is it also like that to use ?
Can we use our own IP camera’s, or is it a must to buy the Stijnen Solutions CCTV to IP server box ?
Any competetive alternatives ?

Is a digital twilight sensor working satisfactory ?
How to put this ‘in series’ with an other initiator to trigger a light ON action f.e.

Where there are a lot of buttons, i would use a vmb8pbu modul behind each cover plate.
That will be in living room and such. With feed back LEDs.
For small areas, less buttons, i would use SVV cables running to a vmb8pbu in the switch box. Also with feed back LEDs at each button.
(Will require some extra hobby time fabricating DIN rail supports for the k8064 dimmers and vmb8pbu)
Am i overlooking something what might cause interference ?

Please note that we do not recommend to extend the leads of pushbutton modules.
The inputs are designed to be close to the pushbuttons. Interference, lightning, spikes etc… can be easily pickued up if you extend the leads.
For longer wires, we recommend the 6-input module (VMB6IN), it features fully buffered and protected inputs, however there are no feedback leds.