In Bloodlines, the whole plot is entirely possible and explainable[footnote]otherwise, there are some inconsistencies with the source material, for example, gaining too much power too fast, but that can also be explained by Bloodlines being a video game and adhering to video game rules[/footnote] when you bear in mind that the whole world is ending. There is the Withering that comes into play several months before Gehenna, and for all we know, Gehenna is right around the corner from the Bloodlines timeframe. Anyway, the Withering basically wreaks havoc with the vampires and their powers. Mostly, anything vampiric starts to slowly break down and weaken, but occasionally, and especially in young vampires, the reverse is true. They gain quite big vampiric powers for a limited time - a week, a months or two. So, while the PC strong, also other vampires would start getting weaker. It starts from the most powerful vampires and it moves down, which means that certainly some of the enemies, and even the bosses, could have been affected.
Also from Bloodlines - the Prince asks you to fetch werewolf blood so it doesn't fall into the wrong hands. This is good and all, but actually, werewolf blood is no different to human blood under any scientific examination. It is very likely vampires would know that, too. But there is something else to the blood - it is much more potent than human blood, and vampires do know that. Furthermore, the blood acts like speed or PCP on vampires and it's easy to get addicted. With this knowledge, it seems that LaCroix most probably wants the blood to trade for a favour with somebody (or to use it himself...but I'm not convinced he's hooked).
Still Bloodlines - Gary is the Nosferatu Primogen in the city[footnote]quick catch up for people who didn't get that. Nosferatu - one of the vampiric clans. Think breed. Primogen - erm, think member of the local vampiric Parliament, who represents their clan.[/footnote]. So he's (one of) the oldest Nosferatu in LA it seems. Or maybe not. The Ground 0 computer reveals that Gary Golden disappeared in 1960, which makes him a vampire for about forty years. That's fairly young in Kindred standards. It is therefore a good guess that Gary joined the Camarilla and was given power and and a high position for it.