Ibiza Mk3, radio/amp

[logistic]

Getting my Ibiza Mk3 next week and im just getting my head around this now and i have a few questions. For the moment all i want to do is run a 2 ch bridgable 400w amp to a sub. A new HU and speakers will follow later down the road.

1. Does the standard radio have a remote connector. If so what does it look like. So i can connect it to my amp.

2. I understand that i need a speaker to RCA convertor to connect my RCA cable from my amp to my hu. Ive read an "Alpine speaker to RCA convertor" is recommended for best quality. Would this be correct or is there a better convertor. Also at the HU what does the convertor connect to. Does it connect to a speaker output. Does that mean i will loose a set of speakers as the convertor is attached?

3. Later down the road i will invest in a new HU with RCA pre-outs. It seems that the best place to mount it is under the steering wheel. How do you connect up a new HU. Does the existing HU have to stay connected. Is there an adapter to use?

4. Last question. The connector in the boot for a cd changer. Can it be used for anything else bar a cd changer. Is there any adapters that can be used with it to expand is capabilities.

Thanks in advance. This will clear up alot for me.

[logistic]

Attached is a pic of my amp. Can i connect the rear speaker cables to the high input on the amp (4 pins)?
Whats the quality difference between using the low input to using the high input? Im using the standard HU.