basement bathroom plumbing

my house has a bathroom drain plumbing rough-in in the basement floor. there is a 2" stub for a sink, a 2" stub for a shower and a 4" stub for a toilet. both 2" lines are connected to the 4" line which is connected to tank where the pump goes. none of the pipes run for more than 6' under the floor. the rough-in also came with a 2" vent pipe and a 2" drain line located at the cieling. the drain line runs horizontally about 8' across the underside of the floor joists, then it turns 90 dgrees upward for a few inches, then it turns 90 degrees horizontally where it runs about 10' to the house's main drain line. couple of questions:

i know i need to vent the tank, but do i need to vent the sink, shower and toilet separately?

do i need to consider anything except the verticle pipe length when figuring the head against the pump (like elbows, horizontal pipe, etc)?

how close to the pump is the check valve supposed to be located?

Take some pics and make a drawing...
It will be easier to give you meaningful answers with all the info...

here are the photos and diagram. under the bucket in the floor is where the shower stub ends.

I usually install a check valve then a ball valve about a foot above the lid. the head on the pump would be the total elevation change.

thanks for the reply. i added two more pics of the drain pipe rough-in. should i be concerned about the horizontal length of the drain pipe? it's about 8' long and turns vertically for several inches before turning horizontal again. the last horizontal run goes to the house's main drain line. Also, do i need to vent the fixtures or just the waste tank?

vents

The fixtures have to be vented, somehow. How you do it depends on several factors, which is why plumbers went to school for 5 years. The 6' distance is immaterial.

According to IPC you can have up to 97' of developed length with a 2" diameter vent and a maximum pump discharge of 100 gpm (which is way more than any home should ever need) Your sump will probably hold around 33 gallons or so and the pump will kick on somewhere around 1/2 capacity so what I am saying is that for your application there aren't any real developed length limitations. Just make sure as you are already aware that the pump will handle the head requirements. You may also tie the sump vent and bathroom group vents together and then make your connection to the "future" vent as long as you are not trying to use a pneumatic sewage ejector (which I have never seen nor heard of and which you certainly do not need). If for some reason you just have to have a pneumatic sewage ejector then you can still use the future vent for the bathroom group but the sump will have to have it's own vent which must terminate in fresh air above your roof.

If you are not under IPC then forget everything I just said and find out what the requirements are under UPC.

P.S. when you install your pump take great care as to how you connect the float switch to the discharge pipe. If the pump has a pre-installed float on a vertical rod then no adjustment is necessary but if it is simply a tethered float switch keep the line short, attached low enough on the discharge line so that the pump will start prior to the sump level reaching the level of the inflow, and oriented so that none of the inflow lands on the float, and so that the float has the least possibility of getting stuck or caught on anything including the side of the sump wall.

Also read the install instructions carefully not all but most pump manufacturers will instruct the installer to drill a 3/16" vent hole in the discharge piping inside the sump. If this is required and you do not do it you will replace the pump inside of one year.