Why not? It's your quilt and if doing both hand and machine quilting is the way to get the look you want, go for it.

I am new to it but am reading an excellent book on machine quilting - how to use a walking foot for SITD and way beyond (which I can't remember the author of and am at work) and she shows examples of doing just that. The photos show how the hand stitching in areas she wants to highlight contrasts nicely with the precise machine look of SITD or near-ditch lines. Also she suggests trying wavy embroidery stitches.

of course you can do machine and hand quilting on your quilt- some of us do that quite often, and i also do machine and hand embroidery and machine and hand applique on the same quilt-
it will turn out just fine. and visit some of the big award winning quilters sites- you will find they mix techniques alot too
it is your project, do what you want to do to reach the conclusion you seek

I've used hand and machine quilting on the same quilt. Unless you're planning for this to be show quilt that requires one or the other, but not both, don't sweat it. I started hand-quilting a baby quilt, then did the final border by machine so I could get it done and out the door. The mom loved that I was able to hand quilt part of it. The baby's 3 and they still love it :-).

I've done both on one quilt and it came out great. I did the straight lines with my machine and walking foot and the curvy stuff by hand.

mixed mediums
mixed textures
applique and quilting
embellishments and quilting
YES. YES. YES, by all means --quilting is your preference and choice. All work well in the same piece.

I have done both! I hand quilted the middle and machine quilted the border. I think I was just tired and wanted to finish. My nephew and his wife loved the quilt. :D

I have a quilt top that my GGM, GM and my Dearest mom all worked on(at different times) The top is hand sewn on the blocks(Broken Texas Star) and the blocks putting everything together is machine sewn. I wouldn't take anything for this top. So do what you want to!! And remember...Have fun!!

I am so glad you asked. I was going to ask that myself, so I, too, will be interested in the replies.

Someone mentioned the "quilt police." I read about this some 15 years ago so excuse me if I get some facts incorrectly related here.
Did you know that there really were quilt police in (I believe) southern Italy? I cannot recall but there is a town that is historically famous for the first whole quilts...even under garments and bodices of the very wealthy were quilted. The work is amazingly beautiful.
The "whole quilt" movement was stopping sale of other related products so the merchants paid the mayor of this town to get a law passed.
It was illegal to have anything "whole quilted." So the story goes, the police would stand outside the windows of wealthy people having parties and arrest anyone wearing something whole quilted...hence "quilt police." (If you are interested, and it is an interesting story, look at the history of quilting.)