In the interests of curiosity, I created 50 accounts on my Windows 7 Professional VM.
net user testx /add where x was a value between 1 and 50 (inclusive).
While I realise this is different to Home Premium, I can at least answer the second part of your question: it looks ridiculous.
This is on my Windows 7 Professional virtual machine running in VirtualBox:
I imagine with the Local Policies you might be able to change the default login screen.
To change the login screen to show Ctrl + Alt + Del prompt, use
netplwiz from an elevated command prompt, click on Advanced, and select "Require users to press Ctrl+Alt+Del".
As @BloodPhilia has pointed out, you're only limited by resources, but I'd say if only two or three people are logged in at the same time, you'll be fine.