There's no issue with pulling other mods to pieces to see how they were made. That's an excellent way to learn and I encourage all people new to modding to do so. Acknowledgement for such a thing is not required, although it is common courtesy. What is against the site rules is stealing/claiming someone else's work as your own, or reusing/redistributing someone else's work (in whole or part) without their permission.
As far as LIP files go, they must be stored in a MOD for the specific module they belong to, placed inside the Lips folder. In your case the module you are working in is the Lehon Central Beach, UNK_M41AA. The associated MOD is \lips\unk_m41aa_loc.mod. Each LIP file name needs to match the VO_ResRef for the associated line in the DLG. For example, Mission's "No - this isn't happening! It can't be happening!" line in unk41_mission.dlg has the VO_ResRef nm41aamiss04000_ and has a matching nm41aamiss04000_.lip in \lips\unk_m41aa_loc.mod.
As with many first-timers, I gather your intention was to just dump a manually edited DLG into the Override. I would strongly advise against this. Doing so creates compatibility issues. Since you'll need to dynamically inject new LIP files into an existing MOD (doing a hard overwrite of that is also strongly advised against), you'll have to learn how to create a TSLPatcher setup. While you are at it, you can also have it dynamically patch the DLG in another MOD (this time for the module itself) in the Modules folder. This will likely take you a while to wrap your head around, so I would suggest the first thing to do is to download TSLPatcher and read the included PDF for an overview of how it works. Once you have done that, come back and provide details of all your mod's components (specifics of exactly what you have changed and how) and someone can guide you through creating a setup for it.