You'll have to adjust the UI and resolution to your liking in the web admin.
The JavaMO article in the wiki mentions this:
Go to the Orbiter in the pluto-admin web interface (select Orbiters in the Wizard on the left) Adapt the PK_UI, PK_Size and resolution values to match your phones display. If you have no touchscreen on the phone stick with symbian for PK_UI, otherwise choose the normal variant.
So, if you select UI1 as your UI, I think you should be able to use the touch screen. You will have to both regen your orbiter and reload after the regen has finished to apply your new selection.