The pump thread sealant is likely because the slip portion was done after the thread sealant. You want no movement after thread sealant. The amount you used looked perfect. You want a nice solid bead around the top. Turn the valves off and unthread the union nut. You don’t have to empty the lines but may need to temporarily support them while the pump is out. Should only take a half hour or so.
The elbow can be fixed by emptying the line, drying the leak area and applying some weldon like
mrrobxc
suggested or even more of the cement you have now. It will not look great but applying more cement over the top may stop it as well if small. There are other products like putties etc that can be used as well.