I am planning my second RTW trip and am concerned about the ability to make a quick transit at a few airports. Specifically, is is possible (and practical) to make the following same day connections at:

1. DPS, CX785-CX784, 1:25 (layover time)
2. DEL, CX753-CX752, 1:55
3. HEL, AY832-AY891, 0:55
4. SXM, AA667-AA660, 1:19

I will be in "D" class but there is still the question of whether it is necessary to clear immigration & customs at the above airports versus utilizing transit facilities, if they even exist!