1.8.3 isn't meant to be installed on an existing install anyway, so that point's rather moot overall.
I can't say I have that happen, many conversations I had with him where they just passed along without effect. Must be one of your mods.
Fixed in today's little "patch"
Not really, no. Maybe if one places an invisible really low on the PC's location, but still it's questionable.
Yes (but I'm not doing it), no.