1) No, model then layout the UVs. If you layout the UVs as you go then you're putting in WAY too much effort for no gain. If you lay out the UVs then change the model then you have to adjust the UVs again. Do it once, do it well.
2) Remember the purpose of modelling one half and then duplicating and stitching? It's to reduce the amount of work you have to do on a symmetric model. Same thing with UVs. Model one half, then lay out the UV's. Duplicate, negative scale, then flip the UVs on the duplicated part.
3) can't give an exact number but not as many as you did . Then again, it looked like you smoothed your model so that's fine. Number of polys should be determined by the purpose of the model. If it's a small thing that no one is going to really look at and analyze then low poly is fine. If the low poly is noticeable then smooth it up as much as you see fit.
if I were you I'd start by doing a cylinder map then going in to all the edges where you want a seam and cutting them in the UV editor.
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D