User ID without email address

[war_is_peace at privatdemail.net]

Hi,

I'm planning on finally uploading my key to a keyserver. Now I had the
idea to add a primary user ID which contains only my name and no email
address. The reason would be that i won't "lose" any signatures if I
change my email address and revoke the then obsolete user id.

Does that make sense? Are there known problems if a (primary) user ID
doesn't contain any email address?

Another question: What is the common practice when signing a key
regarding its user IDs? Should you sign all user IDs, whether you
checked if their email address belongs to the key owner or not? Is it
common to verify the address at all?

Greetings,
Flo