I think it sounds great! 
I think your issue with the white flower and pearlized white body could be solved by the actual color of the body color.  If you can get your body color to be just a little off-white (not too much!) and then use a stark white for the flower I think you would be ok.  If that doesn't seem like it's going to work, you can always try outlining the flower in a pastel yellow or pink instead of black.  That way it keeps it nice and soft instead of using hard black lines
I honestly use FolkArt acrylics and water them down so they don't dry out and get clumpy.  Unless I'm using white, and then I go with a better quality brand name because the cheap whites are never quite white enough and are usually pretty thin.  A couple more dollars and you get an awesome amount of pigment from a higher quality paint
As for sealers, a lot of people use Testor's dullcoat, but I've also seen Modpodge used a lot too.  I'm still trying to find what I like, but I had great results with the glitter Modpodge I picked up a little while ago
Hope that helps!

Thank you Tina I just placed my order!

I would love to add her someday if her price goes down!

I broke down and got her off ebay :\  But I did pay less than what most of them are going for so I feel good about that.  Everyone was battling it out over the listing for the Mane Six Fashion Style group

Thanks, the US site only has preorders available for black saran, but I'm seriously considering ordering from the UK site and just waiting a little longer. 
I've never dyed before but it might be good to learn, Thanks!

Hi everypony!  I'm in some serious trouble here if I can't find some black hair.  I'm even willing to take saran at this point.  Everyone is sold out!  And I have at least 2 customs that need black for their manes and tails... Help!
I have:
Small amounts (might be enough for a G4) of Poison Ivy, Key Lime, White Witch and Starlight
1/3 to half hank of Lemon Drop and a 2/3 Black Magic 1/3 Mermaid mix
Nearly full hanks of Moonlight and Rain cloud
Please and thank you!

An exacto blade is definitely the best way to get the head off, but make sure you pull on the head so that the tension helps the glue release (i.e. pull the head back towards the rump to cut the very front part of the neck -between the two front legs).  You get a smoother cut than if you just saw away at the plastic.  You might need an extra set of hands if she's being stubborn.
When you're removing the hair cut it nice and short, as short as you can get it, and then use needle nose pliers to pull it out.  I've found that with the right amount of grabbing and twisting it comes right out without the need to boil or weaken the plastic.  In really stubborn cases, a Q-tip with a little acetone helps immensely. 
When you're rehairing, you'll notice your hank will separate into little "clumps" of hair.  I normally use that as a guide and try not to go too much larger than that when making my plugs.  If it does split (which isn't often), it's normally only into the next empty hole and I just add another plug to the new larger hole.  Your bait isn't that old so you shouldn't have too many problems
Best of luck!