Basement bathroom questions...(ejector pumps?)

I have one, but just to boost my washer waste to the pipe, which is near the ceiling. Had it a couple/few years with no issue. There is a 2-3' pipe for venting attached with a simple check-valve type deal built in.

I had one for a full bath - large whirlpool tub, shower, toilet, sink. It was set into the ground under the floor with an access hatch, and pumped up over the ceiling, then down to the drain which was about 3' off the floor. Going up and over was the best way for me. I used it for about 4 years before I moved, and never had a problem.
One caveat - make sure the pipes are well secured. Mine weren't, and whenever the pump started, the pipe would bang against something. Since it was all boxed in, I left it alone. That bath got plenty of use. If the pump had needed attention, it was easy to get to, but hiding the access hatch could be a problem if you have a tile floor, say.

Since the pump/tank were below floor level, everything in the bath was on the floor, not raised on platforms, so if you didn't know, the bath could have been above grade.

they are common and work well,,,some are called "grinders" when you go looking.

My sister has a sewage ejector pump (sewage grinder pit )and the tank is vented into the existing vent line of the house DWV 2".
It is mounted in a tank in the floor and all the drain pipes are under the concrete floor.

I just had to add a small lift pump ( and plumbing through the ceiling) for a new downstairs kitchen sink . The existing sink drain ( no one was using it ) that we believed tied into the DWV under the concrete floor just exited into the ground through a hole punched in the floor. That couldn't have worked for more than a week before the ground got saturated.

We installed a saniflo solution in our basement ( sink, toilet - rear discharge, shower ). Had it for approx 5 years and absolutely no issues.
It is mounted behind the toilet, you can get an extension and mount the toilet behind the wall.

We call it the blender......

As for venting mine - they had to run a separate vent line up through the attic to be legal. They weren't going to do that until I said I was getting the job permitted and inspected.

Below the floor, pumps up and out the sewer line about 5' above the floor. Toilet, sink, shower. Replaced the pump once in 23 years.

I have poopy pumps for my whole house, the waste line empties into a concrete tank 6' deep x 5' dia in the backyard, two sump pumps pump sewage about 50' to the town sewer. Had one pump fail 2 months ago, It was over 20 years old. I had to go down into the tank and replace the bad one.
I used one of the harbor freight sewage pumps, it is working fine so far, the HF one is about half the weight of the original, and seems to pump faster.

I have a whole house grinder pump, outside. I think you can get a flush up toilet.

I had a duplex, over/under. The lower unit needed a septic ejector pump, but it pumped the entire apartment, (kitchen and laundry) not just one seldom used bathroom. I had to replace that pump about every two years or so. Nasty job it was too.

Working as a plumber for many years I saw a few different systems. The best overall is the below the floor tank with the heavy duty grinder and 2" vent. These are mostly used in new construction and the piping and pit are laid in before the floor is cast.

Another alternative involved raising the floor six inches and installing a flat tank under the floor. This system was the most complex, as it required an access space behind the bathroom the service the pump, I only saw it used once and am not sure why it was chosen. The subfloor of the bathroom lies directly upon the top of the tank, and great care must be exercised to avoid screwing the subfloor to the tank. The only benefit was easy access to a heavy duty 2" grinder pump. (changing a pump in a floor pit is a nasty job).

The third, and best IMHO is the flush up toilet with the built in grinder. Main advantage, this thing grinds so fine and pumps so well that discharge is through a 1" pipe.
Only disadvantage; the shower must be raised 6" in order to drain into the toilet's pump chamber. Can't remember the cost, but considering the advantages, is likely the best method.

Research macerating toilets or pums.

I was about to pull the trigger on the a pump/basin combo for my basement wet bar recently until I found another alternative for sinks (would not work for toilets).

The biggest concern I had with the pump/basin setup was the venting. The more I dug in the more I was confident that (at least in Michigan) the vent for an ejector pump had to go to the roof, by itself, and I don't think it could share a vent with any existing fixtures. I have a two story home and the thought of adding a vent for this application was highly discouraging. Until I found the vent-free sink pump option I was considering a non code compliant install. Without it, the wet bar was quickly becoming a dry bar.