How to take Processing/Scalloping losses in account in SNR/SFDR/THD/SINAD calculations?
Some of the window performance metrics associated with the DFT are covered in great detail in:

F. J. Harris, "On the use of windows for harmonic analysis with the discrete Fourier transform," in Proceedings of the IEEE, vol. 66, no. 1, pp. 51-83, Jan. 1978.
doi: 10.1109/PROC.1978.10837
Abstract: This paper makes available a concise review of data windows and their affect on the detection of harmonic signals in the presence of broad-band noise, and in the presence of nearby strong harmonic interference. We also call attention to a number of common errors in the application of windows when used with the fast Fourier transform. This paper includes a comprehensive catalog of data windows along with their significant performance parameters from which the different windows can be compared. Finally, an example demonstrates the use and value of windows to resolve closely spaced harmonic signals characterized by large differences in amplitude.
keywords: {Discrete Fourier transforms;Fourier transforms;Frequency;Harmonic analysis;Oceans;Parameter estimation;Signal processing;Signal resolution;Signal sampling;Smoothing methods},
URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&amp;arnumber=1455106&amp;isnumber=31261  Non-paywall version here.

Not all the metrics you ask for are covered, but there are several which you haven't identified that are discussed. Perhaps if you said more about who might be interested in using your library, more specific suggestions are likely to be offered.