PETERNLEWIS  Each Macro Group can be targeted at a set of applications, so create two macro groups, one for each application, and put your two macros with the same trigger hot key in the two groups and you'll be good as gold.  
(Version 3.4)

PETERNLEWIS  Turn off Preferences -> Always Show Status Menu and the menu bar will not be added until you have an active Status Menu triggered macro. Enjoy, Peter.  
(Version 3.3)

PETERNLEWIS  According to Activity Monitor, on my Mac currently, Keyboard Maestro and Keyboard Maestro Engine and Keyboard Maestro Web Server currently show use of 0.0 CPU and 8.5Meg, 8.3Meg and 1.3Meg of real memory.

For comparison, some other real memory uses: Activity Monitor: 14Meg, DragThing: 16Meg, GrowlHelperApp: 17Meg, KeyCue: 15Meg.  
(Version 3.1)

PETER N LEWIS  Interarchy 7.3 release suffered from a compiler glitch in the final build causing the crash. It was fixed in 7.3.1 which we released within about 8 hours of 7.3 being released.  
(Version 7.3)