How to verify that the Unofficial Patch was installed for Vampires Bloodlines

I've compared 3 presets: Gionight, Confident and Nightwalker. The best is from Gionight. It has the best colors and it runs good on low quality settings. Here is a Download-Link: http://www.skyrimnexus.com/downloads/file.php?id=5516. The one from Confident is pratically the same like the default preset and very blurry and weak colors and the one from Nightwalker is too dark or the colors is too extreme and it's not very balanced.

The 'Argonians no longer gasp when leaving water' USKP fix is affected by the issues described in this USKP thread post in the Bethesda forums:

Skyrim Patch 1.6.89 introduced one critically bad bug:

Edited vanilla dialogue causes the audio and subtitles to fail to display. Papyrus fragments attached to failed dialogue will also fail to execute.

As a result, ALL edits to dialogue of any sort have been removed.

A temporary update for the USKP has been issued to address this, but it isn't entirely without use as several other bugs which can be safely fixed have been.

An easy game mechanic check to see if USKP is working is this (from v1.0 - 2012-04-07):

NPCs will no longer drop weapons or shields as separate objects, as these are never cleaned up which greatly adds to save bloating and litters the gameworld (the items will still appear to be dropped, but will access the corpse's inventory to be taken and be cleaned up with the corpse if left)

For other USKP changes you can check, see the Complete list of USKP fixes.