Changing the machines volume depends on the technology of the machine and sometimes also the manufacturer of the machine.
Press + and - on the keyboard (depending on device you may need to press Cntl or alt with - and +) with any layout loaded will turn up and down the sound in the emulator but may not be loud enough still, if the machine is set to very low sound.
On most Scorpion 4 tech machines after loading the machine, press F9 to show the doors and meter bars if they are not showing. Then tick the S door box.
Once the machine shows read meters, press the test box (near the S door box) and then use the buttons flashing (not start) to scroll through until you find volume. Then press start and you should be able to turn the volume up and down using the flashing buttons normally cancel and hold 1 button. Then press start to come out of the volume control, then untick the S door and let the machine initialise again.
Also don't forget to see if the volume for MFME is low, by opening the volume controls by the clock on the windows taskbar.
To stop the constant payout sounds, press Cntl E to enter edit mode, then click on the configuration tab.
Remove the ticks from hopper 1 and 2.
Close the configuration tab.
Now press Cntl E to come out of edit mode.
You can then either reload the machine by clicking file and selecting it and save changes.
Or you can press Cntl R to just reload the machine (simulated switching the machine off and back on again). Then when you finish playing and close the layout save the changes.
The refill message is irrelevant, but if you really want to try to get rid of it, try creating a checkbox 32 and see if it goes away.
To do that again press Cntl E for edit mode.
Right click on a blank part of the layout I. E not on a lamp or button, and from the menu choose buttons then choose checkbox. Right click on the checkbox and choose properties and number it on left hand side of the properties screen 32 and tick it on the right hand side of that screen, you can also change the 0 in the bottom left of the screen to 32. Close the properties box.
Come out of edit mode (Cntl E) and reload the layout saving changes when asked.
The ram message may go away by itself the second time you load a layout. Also make sure the layout isn't in read only mode which it would say in the title bar after loading the layout, next to the name.