This was implemented in chromosome beta, but I guess someone accidentally switched it off post Uprising. For now you can use this page for the maths as its the same as Eve Online..

Since I use the Scrambler Rifle, I would like to know how much damage I do to armor and shields. I don't really know how CCP adds on my 10% damage boost, my 5% damage boost, my Level 3 proficiency, and the 120% to shields and 80% to armor.

+1 same thing for stats on ships for instance. Now there is a resistance % for armor but not for shields. I find that the new stats with 1% resistance per level to the assault DS is confusing since it is not told if it works on active modules that improve resistance. No mention of stacking penalties either. These things are important to be clear and understood before making a commitment in SP. Which brings me to my next point...RESPEC.

Yes it does. Stacking penalties would be applied even though they aren't the same exact module. Having the same bonus category is enough.

Also, this was removed after Chromosome, not by accident, but because the display was inaccurate and also because a single number couldn't convey the reality of the suit. For example, suppose you have a complex light damage mod and an enhances sidearm mod, what's the single number for this? That's why the number was removed.

Now, having said that, I support better stats in Dust, but be prepared for all the math challenged out there to whine on the forums when they put two complex damage mods on, and see a total bonus of 19.6%, and can't figure out why it isn't 20%.