Very nice project and a great start!!
I'm definitely in and will be following, a very entertaining blog so far, just read it from the beginning.
I can't be of much help with this kits, but maybe for more general questions of yours.
Most was answered already. Maybe my five cent - be careful in 'simply' following instructions! If you just end up building subassemblies that are not needed for the next weeks or month, so what. But sometimes there are steps that simply don't work, or entirely mislead you when you try to follow. That is no speciality of Dragon, it is the same with Trumpeter, most aftermarket producers, Heller...
Consider at what point you paint stuff. That may deviate from the wings side, as well. Many subassemblies must be painted before they are installed on the ship, otherwise you can't reach them. Others should be painted after installation, to blend in. There is not the 'one way'.
And the 'spare' guns and parts you see, that's just 'laziness' on part of the manufacturers. Or it might even be more economical. When a base kit is sold in different versions (as yours!) you'll likely find the number of guns etc... required for the version of the ship the needs most. It's probably cheaper than having different types of sprues with two or three items.
And I don't start with the big guns - I do like them too, very much so. BUT - when you do all the fun stuff early on and find yourself with all those parts left to do that you don't like that much, you're likely to lose motivation towards the end of a build...just my approach