Is it possible to show the new clef following a change, in the ‘normal’ position and size: after the barline?
Hi! I’m not at my computer right now but I remember there are useful options if you select the clef and invoke context menu > Clefs. I hope there’s a solution there for you 
I can’t think of a good way to make a clef change appear after the barline. Assuming you don’t need an actual coda in your music you could create a coda there and set the gap to zero spaces in Engraving Options.