In a 2D roof takeoff, I use the area (either using Takeoff_Area or assigning cost data to a Material in Estimator) and then in Estimator, I use a multiplier to convert the area to the sloped area and then assign pricing to this area. For 3D roofs, I just use the area of the actual sloped faces (via Materials in Estimator) – so, to answer your question, I use two different methods depending on whether a 2D or 3D takeoff.
Takeoff_Length is free to Estimator customers – the reason I created it was the only way I could get accurate length data in my models was to use Profile Builder – while it is generally the most common way I do it, Takeoff_Length gives me much more flexibility to not have to carefully model everything. Both work – NO, you do not need PB2 for Estimator to work, simply a great companion tool – I use it to model so many different items (framing, trim, etc.) AND get takeoffs in addition.
Takeoff_Area has a free trial but is $25.
Regarding finding a cost item from the interface – Estimator is real-time and reports the results of whatever is selected in SU. So, you have to have a selection in order to view costs. I am working on some other ideas for this for future, but for now it is how I want it handled. I like to be able to view costs for various phases or purchase orders (like a scene with my various framing packages per level) – when I want the total costs, I simply pick everything, check “include quotes” and “include margin”
Hope this helps