Yes, when the user starts picking a fault in the IL direction, he can keep picking the fault in other directions such as XL, TS and even on horizon stacks.
Yes, it is possible to merge 2 or more faults. It is also possible to split a fault which has been previously merged.
Yes, the user needs to click on the "EDIT" icon in the Fault picking module and then double click on the fault that he wishes to edit. He can add, move or remove fault sticks.
PaleoScan can deal with reverse fault by generating two horizons for the same event (like other applications). In case of a steep dip, everything works fine. In case of a low angle fault, PaleoScan can handle the reverse fault if there is a low throw