No one can just drop anything. You can put your entire line up for giveaway. You can give your whole line away and not work at all, but you aren't going to get paid either. There is no minimum.
Good to know. If you tried giving away trips do people normally pick them up? ie. could you plan on doing that or is it hit and miss as far as the trips actually getting picked up? If on reserve can you give away reserve days? If not, how could you adjust your reserve schedule. Assuming you didn't mind small paychecks but want to maximize time at home whilst keeping the SWA seniority number.