Q:

What % of bitcoin transactions involve addresses of known charitable organizations

Blockchain analysis can come a lot way. Are we at the point where we can identify what percentage of transactions related to certain industries?
What percentage of transactions involve a receiving address than can be tied to a charitable organization with blockchain analysis?
If that question can be answered please also list any bitcoin transaction size data that is available.

A:

Are we at the point where we can identify what percentage of transactions related to certain industries?

Not really! The percentage of addresses that are tied to known organizations is quite small. You also have to consider that many transfers occur without any change in ownership, that is, a person sends bitcoin from one address they control to another. 
Consider the mining industry: we know the address of every mining pool that finds blocks, because their address becomes known at the time of the block being minted. Even then, if the coins are transferred to other addresses within the mining organization, we lose clarity on whether these coins are still being held 'within' that industry, and are left to IP analysis, which is far from conclusive in many situations.
If you made a list of known addresses tied to charitable organizations, you could easily come up with a percentage of total transactions associated with those organizations, but it wouldn't be that meaningful of a statistic.

