Yeah, badly deployed clip art or whatever seems pretty common in manhua now.
darn you really cited your sources. personally these are not dealbreakers for me long as the main characters are illustrated in a style I enjoy, but try as I might to not notice them the egregiously done examples do still bother me sometime.
But I think most of the manhua I follow has bad art problems. I think Green Tea Bitch is okay, though.
GTB is my favorite yuri manhua ever and it's not even close :P
the backgrounds definitely have taken some shortcuts (if we were to define shortcut as in not hand-drawn) using models or photos perhaps with filters applied on them, but it never made me groan of just how jarring it looked the way some other webcomics' backgrounds have made me.
also I noticed that in manhuas there seem to be an inclination to draw every single frame of the main character as "sparkly" and as "flawless" as possible, to varying degrees of success (in my opinion). this manhua 'my heart is not a stone' is a pretty good example of it done well. GTB did no such thing but it's still quite easy to tell just how skilled the author is and the style's so ever charming.