To be honest I'm not too keen on any of the Echo SL parts. Apart from the freewheels because apart from that they just try and make everything as light as possible which results in it being weaker. I would go for the Echo Urbans at the same price (depending what mounts you choose). They are about 100g heavier I think but should be much stronger. EDIT << They are 100g heavier for 26" and 200 for 20"
I used to not be able to sidehop anything then one day it just kind clicked I still can't go very high.. Ages ago I used to sidehop to the right (I'm right footed) and then I got told to do it the other way. I found it much easier and it felt a lot better after I got used to it.
Yes. However I think most people would prefer not to reduce strength at all. Also if its where the pedal goes in that it hits this wouldn't work unless you grinded the pedal axle too which would make the pedal or cranks more likely to strip where the pedal goes in. A longer bb is the best idea.
Its not snapped. Its just come out... I'm not sure where you could buy a new one. But if you can find somewhere that would sell one then its probably replaceable.
Its probably the prongs from you brake rubbing on the rim. Check to make sure this isn't happening. If it is you will need to set your brake up. For the flex definitely get the Trialtech Sport booster.