I have downloaded Tux's map lag test at http://www.staredit.net/maplantis/index.php?sid=a54eae177e;map=399

Whereas that map showcases which actions lag the most, it does it for 1000 units. Its purpose was to determine which actions were the worst, not what was the acceptable amount. If I understood it correctly:
- remove and give and move units are the worst offenders
- kill is laggy, but surprisingly not as much as the others
- orders are laggy only when continuously used with units near each other. I think this is due to the zerglings trying to find a path when there was none, so air units are probably exempt
- create was never tested alone, but it still seems laggy
- ai scripts (well, only junkyard dog was tested) seem to have little lag
- center loc, center view, remove/give/move/kill with no units nearby, and orders when units were far enough had little to no lag

In my map, most of my laggy actions are not continuous. As in, several gives/removes/creates/etc. will happen only when the player casts a spell or periodically every couple of seconds. That kind of lag won't really be that noticeable as it isn't continuous. My problem is when there is a continuous use of laggy actions.

At the moment, the only continuous laggy action I have is during a spell (it lasts around 5 seconds) where I need to constantly cycle through 22 units to check which enemies are nearby. I'm cycling through 22 Interceptors and 22 Carriers (1 Interceptor per Carrier). Technically, that's 44 gives, as it's 2 units each to check each unit, then another 44 at the end to give them all back to the original player. That's 88 gives per trigger loop. I'm worried that 88 gives like that will cause lag considering all the other units and triggers on the map.

So, if anyone knows, what is the acceptable maximum number of laggy actions per trigger cycle such that the map is still playable?

If your tests are not lagging, chances are it won't lag in-game either. Usually any actions that involve units, other than centering locations, cause more lag than anything else. If you do start lagging, you can do what Tuxlar ended up doing and slow down your hypertriggers so the triggers don't happen so often, although with the systems you have, maybe that isn't an option.

Of course, it really comes down to internet speed and computer speed, if someone has a crappy computer, or 56k, they're going to lag, and there's pretty much nothing you can do about it.

Connection speed has no influence on trigger lag since triggers are calculated locally.
Sc only transfers player input such as mouse clicks and movements.