So let me get this straight I need to use /endmacro kissassist or is it just endmacro which will end all macros running at the time correct?
And from the second question if I do 8 on all my toons who will dps target to 98 or will tank just know to engage at 100%.
The terminology can be a little confusing at first. Using /end will turn off KissAssist (often referred to on the forums as KA). KA is a macro that has many (for lack of a better word) smaller macros that work on an if/then flowchart. <IF action A occurs><do action B>
If you set /assist to 98, each toon that is set to that will engage the mob at 98%, not before.
Personally, I created a hot button in game(again, the wording can be confusing) to look like this:
/dge /assist CharacterName
/dge /pet attack
/dex CharacterWithSlows /alt activate XXXX.
This hotbutton tells everyone in the group running KA to assist Me, send in the pets to attack the mob, and tells a toon to slow the mob. Easy Peasy.
Also, if you wanted to create a hotbutton to end KA on all toons, it would look like this:
/dge /end
/dge is a command that tells all toons to do the command. /dex is specific to a single Character named in the command. It can seem overwhelming, but take a look at kissassist.com. it is a spreadsheet of available commands, what they do, and how they work together.