I have yet to run into much that does not allow intervening in auto negotiation, managed or not.
Sounds about right. Once you have the SNMP toolset, it's not hard to establish your configuration. But these things confuse people.
Sure.
Thereabouts. IMO, the Ethernet interface is no longer the source of most errors these days.
LOLz!
Yep.
Probably not in residential.
A TDR is just fine so long as you know what to look for and it supports the right cable profiles. I think the certifier we have is like $1K. Might be less - there are a lot of them.
Not having one probably cost us at least an order of magnitude more.
These days, I just want the phone not to ring :)