In the case of your biceps, your not going to use webbing. Webbing is for strapping full pieces to each other, i.e. a chest piece and a shoulder/bicep/pauldron, to keep them in line with each other and not falling.
What your going to need to do is find the contact points for each of those pieces and attach them together based on that, probably with hot glue/super glue, or whatever else your using. Look at the pdo file or get some screen shots to see how they should connect. I would suggest using some scrap paper and making some fake tabs to glue it together.
As to your timeline, you can complete a suit in 2 weeks to a month, but your not going to get the quality of some of the builds here. And certainly not with paper, which really needs to be hardened and smoothed. That process takes about a day per large/full piece, just because of the dry/cure time. That being said, some of the first suits I saw on the old 405th, and my first suit (which I have never shown), were not top quality, so build what your happy with.