Baldur's Gate is not it's own brand or setting, it's apart of the Forgotten Realms, it's a single city within the Forgotten Realms. It's the same world/brand as games like Neverwinter 1&2, Eye of the Beholder, Al Qadim, Pool of Radiance, Azure Bonds, Pool of Radiance 2, ect...
RTwP is not an inheriant trait of the Forgotten Realms, some FR games are TB, others are real time, others weirder things, ect...
And replacing Star Wars characters with Star Trek characters and lore would be a huge improvement because Star Wars sucks, it's the repetitive epic, it hasn't been good since after Jabba the Hutt died and Princess Laia stopped wearing the gold bikini. It's the Cardassian repetitive epic. Star Trek rules, Star Wars drools.
Baldur's Gate is certainly its own brand, just like Neverwinter Nights and Icewind Dale are. They all take place in Forgotten Realms, but that doesn't mean they aren't distinct. Baldur's Gate is THE RTwP game because it created the genre and the RTwP genre came into existence for the purpose of Baldur's Gate. There's nothing else that would be appropriate for it.
Your preference of Star Trek over Star Wars does not challenge the point that to gut an IP's legacy and replace it with another, particularly a competitor's legacy, is to disregard the IP that you're working with. There's no point in working with it in the first place if that's what is going to be done to it.
