How do you adjust a keyword selection?

Hello,

QUESTION: What's the best way to fine-tune a keyword selection, once it's set and you come back to it in the future?

My situation: I've spent 4 hours keyword'ing some sports footage (50 mins). I have about 40 keyword tags along the lines of "Pass", "Goal", "John", "Jane", "Crowd", "Wide Shot", etc. Everything seems cool, organized the way I want and readily accessible. During this time I didn't touch any of my source files, and the program stayed open the entire time.

Problem: When I start looking over some of my keyword selections (e.g. I click the "Pass" keyword and get a list of all clips tagged with "Pass"), some of the keyword selections seem to have timing which is way off. Even accounting for human error, I don't see how I was that off on some of the keyword selections (the in and out time). I haven't had time to thorough go over everything, but let's assume it's human error, and not a bug. FYI, many of my keyword selections are very tight timing situations... like 0.5 to 3 seconds in length. Do you think this is a factor? Something about time scale?

In any case, going forward let's say I need to adjust some of my keyword selections. I would like to simply click a keyword on the far left, then in the list I select an individual clip/keyword. At this point I'd like to be able to start 'swiping' my in-and-out handles one way or the other to extend or shorten a keyword selection. However I can't seem to be able to get a state/view where I can do this smoothely and efficiently? It seems like I can shorten a keyword selection, but not extend it.

The only way I've been able to do a keyword in-out adjustment is to REMEMBER the parent clip name, go to my master list of event footage, find the name in the list and select it, then start going through the yellow boxes until I find the one I wanted to adjust. Now I can change the in-out of the keyword. A royal pain. In addition, during this procedure I'm noticing completely wrong keyword selections (I was shocked). Again, maybe it's human error, but I don't see how I could be so off on some footage?

QUESTION: Are there known bugs regarding my situation, or am I alone and most likely this is human error?

QUESTION: Am I tagging too much and hitting a limit on what FCP can handle with accuracy?

It'll take me more time to analyze the results thoroughly, and reluctant/hesitant/scared of going ahead and keywording other footage for another 40 hours if it's always going to be all screwy. Thus my post on this forum.