1 - subs can come later, when you're ready for 'punch' in your music, and 'rumble' in your HT
2 - it seems like a good match, though I went with the JBL fronts and the rest klipsch because I thought the JBL stadiums sounded better. They also mixed well with the klipsch synergy's
3 - Receiver is great, I have the 1015tx.
4 - go with atleast 16 gauge wiring for your speakers, and bi-wire the klipsch's. as far as cables go, go with your budget. you don't need to pay 'monster' prices to get good performance.
5 - go with a good surge protector / line conditioner, it makes a very noticeable difference