Amiga Explorer is strictly a file transfer solution. It is about as bonehead simple as it gets (with the floppy you can boot the Amiga blind without a monitor and just operate from the PC side), but the Windows suckage does show through. You thought you could map to a drive letter and/or use a .bat script to automate your long, slow copy jobs? Or expect large copy operations to operate unattended reliably?
Amiga Explorer won't forward internet packets, so it won't do what the original poster wanted. I have used the Linux pppd command and Miami to do pretty much this exact thing, for pretty much the same reason: to have Jabberwocky up while ditzing around on my A1200-with-unviolated-wedgie-case. I can't remember, though, how to set it up to forward packets (iptables something...) (It is also possible to use getty, if you want login control).
If you want to do go this way and need more help, email me at catmrad@usermail.there-is-no-cat.com. I've been doing a bit of Amiga resussitation lately and have been meaning to hammer out the details of doing thses knds of things. (If I can only get the Linux affs file system working...)