Complex: Sent Items with Windows Live Mail

I have a new PC with Windows 7 and Live Mail vs. Vista and Outlook Express.
I'm generally unhappy, while realizing that much of that is probably newness
vs. (perceived) inferior user interfaces.

I would love to still use Outlook Express, but gather that isn't an option
with W7.

It's complex as I prefer to give/use a Yahoo address for my email, while
realizing that anything outgoing gets stamped as Verizon.net, my ISP.  Also,
they have differing PW's, although I suppose I could sync that.

It took me a couple of weeks just to get Live Mail working to some degree,
and I got really tired of getting booted out of Verizon / Yahoo Mail every
hour or so, even though I checked "stay signed in" at Verizon.

Outgoing messages from Live Mail do not go into Sent Items, even though I do
have Options/Mail/Send "Save Copy" set to that.

They do show up in the Inbox of my Verizon / Yahoo account.  However, I
really hate that interface and would like to avoid it as much as possible.
This worked fine with Outlook Express.

I no longer have Yahoo Plus (theoretically required for POP), although
everything still worked fine in Outlook Express until that PC died.

Thanks for anything you can suggest to this retro mainframe guy.