I use ConnectBot to give me remote ssh/telnet login plus there's a BOINC manager, AndroBOINC I think it's called, that lets you manage a remote BOINC install from an Android device. The same thing goes for editing the remote_hosts.cfg file as for any other remote host.

Step by step command line BOINC install and upgrade commands have been listed in this thread multiple times.
If the only available network is your WiFi hotspot it should be detected during the install. It needs to be active of course.

Uploading completed units is automatic when BOINC detects a valid internet connection, but if you want to do it from the command line use:
Code:
boinccmd --project www.worldcommunitygrid.org update
If you want to use your Android phone as a WiFi hotspot I use an app called 3G Mobile Hotspot. It has full WPA2 security and DHCP sever built in. Chews through the battery pretty quick though.