Hi. Nick.
There's been literally hundreds of posts coving all the topics you've asked for in your post on this forum.
Such as the vents above windows causing runs down onto glass. I think (I'm traditional here mind) that some said to avoid wetting them.
Also, educating customers about WFP has also been debated. I'm sure there's a few guys here with a 'fact-sheet' that they've given to customers explaining what it's all about, but focussing on the positive aspects for the customer. Have a look in the 'documents to download' section. You may find one there. If not ask here.
Remember, when asking questions I find it best to ask one specific question per post, if you can; otherwise if your question is too open, it puts members off from replying.
If you use the search function at the top of the screen, I'm sure you'll find the answer to most, if not all of your questions
Welcome to the forum.