Deba could play in the NBL in the right team. As long as you use him like a Jason Terry type, come in get some shots up quickly, if hitting the stay with him, if not put him on ice for next game.
You will have to accept his poor decision making at times and lack of defence, but you get an explosive scorer and someone who can ignite a break.
McFarlin isn't a PF he is a straight up C who needs to play 6ft from basket. He would no doubt be a good rebounder in NBL but you wouldn't expect anything out of him in terms of points other than offensive rebounds.
Jazz could be very much like Henry in NBL, up and down but could play for sure. Only question would be over the fact he is so light! Lack of height isn't the issue, it's the lack of body weight.
Other SEABL imports worth looking at -
PG - Mercer
SG - Richard
SF- Wilson
PF - Pichon
C - Gaff