I like them, but I disagree about adding the black checks to the yellow. I think with all the effort you put into the freehand (Very awesome BTW) I like having some of the mini left in a solid colour. If it was painted in freehand as well I think it would just be too much. As it is now, I like it.
And sure, the bases could use soem work to match the quality of the painting. If you don't enjoy making bases I'd reccomend looking at some resin ones. I know Dragon Forge Designs is my favorite and I like the look of their "sanctuary" series for a mini like your Harlequin for sure.