How to calculate signature generation, signature verification, transaction verification speed?
All of these things you want to calculate are highly dependent not just on the hardware you use, but the software you use. For example you can generate signatures many different ways and every bitcoin wallet generates them a little differently. The signature generation performance of Java in bitcoinJ is going to different than that of Go in btcwallet is going to be different than that of C++ in bitcoin core and so on. In addition, deterministic signatures are going to have a different performance profile than non-deterministic signatures and so on.

That said, if you really wanted to, you can run some performance testing on any one of these, though not all of them exist. For verifying signatures in btcd, there is a benchmark test that you can use.

Note that block verification (or creation) necessarily means verification of all transactions in the block as well as checking the proof-of-work. Checking the proof-of-work, by the way, is really as simple as a calculation of a double-sha256, or a single "hash" that mining gear can do billions or trillions of per second.