Bar Tending Active Career

Well, it's not ideal but you can travel to community lots with your sim and "tend bar".

Maybe the culinary branch of the Turbo Careers mod would be what you're looking for? I've never used the mod though so I don't know whether or not it's working.

As for a mod-free solution, there wouldn't be too many options. You could buy a portable bar and a sales table and sell drinks at the club? You could make a restaurant that functions as a bar and only serves drinks maybe?

or to have played sims take over positions for NPCs

I don't think this one is possible
eta: but if you have GT you could also drop the bartender into a club that meets at the nightclub and mixes drinks

"calaprfy;c-16429664" wrote:
Whenever I have a sim in the mixology career, I send them to the karaoke bar in the Spice District in San Myshuno as there are two bars but one NPC bartender. They tend the spare bar and thus work a shift.

Yeah, wouldn't some form of this work? Start out playing the Sim you want to be the bartender, have them tend the spare bar, then switch to the Sim that you want to be the singer. I wonder if the bartender will stay tending the bar when you switch through and reload the lot, though? They might for a short period of time if you give it a shot. They will probably at least stay on the lot for a while. I know that I have done this, and the Sims I switched away from stayed on the lot for quite some time.

Also, if you get a Sim's bartending skill high, they might show up as the bartender, as the game tends to choose the highest skilled Sims. Pure luck if it would actually happen.... :)

If your sim has a portable bar you can set it up on community lots and tend it. It works the same way with the portable DJ booth too.

I'll find some way to work around it but I wish I didn't have to. I want to play them as separate households, however, my track record with having separate played household run into each other tends to be unfavorable.