1. Substitute html or pdf for chm and I like this option. Easy to have the file local, on the corporate network (one place to fix errors), or anywhere. There are much better tools, references and examples for dealing with html as opposed to chm.
2. In moderation, I am usually a bit inpatient with these. They seem to hide when I want them and show up in time to block what I really want. I do not need to know that the button with the stop sign picture is 'stop'. What I really like is when you have a status bar on the bottom of the window and just pop the would-be tip strip string into it.
Context Help: It is probably just me, but I find that a bit klunky for an application. Works well for the BD, but it is growing,shrinking and otherwise distracting. It is easy to learn to love it when you are the developer in charge of reinventing that wheel, but users who do not know or care about the trouble involved may not like it. (Caveat, I am too spoiled by what I can do in other application frameworks, things like balloon popups with html formatting).
I have a pile of Kudos on a different forum because that is a patently false statement.