Hi, Clown loaches get quite large so if it's for the tank listed in your profile I would say no because it's far too small for all the fish you've listed.
If you get a larger tank yes clown loaches can be kept with angels however a betta should not be kept with Angels. With 7 Angels if you want to add clown loaches then you'll need at least a 90 Gallon tank.
The Clowns & Angels are compatible but like Jeff wrote, your tank is nowhere near big enough. I'd say you need all of your 58gal just to house the Angels. Clowns need to be in groups of at least 3 & need at least 120gal for those 3 IMO. The Pleco might be ok or it might need a larger tank, it depends exactly what species it is. The Betta needs a tank of it's own with nothing else in it.
Neither Angelfish or Clown loaches will hurt/ disturb each other Although Clowns will zip through all the different levels of the tank they are basically bottom fish. Angels by the same token are basically top water fish but will check out the other levels.