Hello to all!

I would really need some advice from someone who knows how semi-perms work (and especially Goldwell Colorance Soft Color Foam) before I do something I might regret later!
After a long, strenuous year in Med School I desperately want a hair color change, but not a permanent one. For the past year I have been slightly bleaching my hair (a natural light brown with copper undertones) to an even lighter shade of brown, almost a dark, dirty blonde (and yet it still keeps to the brown side) with copper undertones (my colorist says it's a level 7). I have only bleached it 2 or 3 times in the last year (by spraying a mixture of chamomile, lemon and peroxide and then applying heat) and afterwards only did root touch ups every month or so. I want to try a semi-permanent dye and try to come close to Emma Stone's natural looking medium copper from the movie Easy A - so plan on using Goldwell Colorance Soft Color Foam 7KG and 8K.
I) Should I use a protein filler before dyeing? I've read about the benefits. I don't feel my hair is damaged. I do want an even hair color, a shinier, healthier hair, but I don't want the protein filler to make it impossible for the dye to come out during the next 6-12 shampoos (or to come out unevenly and incompletely). I am afraid that the semi-perm will hardly go out of my hair if I use the protein filler and that my beautiful brown-blonde color will never be the same again.
II) On the other hand, I am afraid that if I do not use the filler the color will be uneven or, paradoxically, it will stick too much to the hair due to its porosity.
III) And even if I don't use a hair filler I am afraid that the color will never come out of my hair and I will end up with a red mess. I only want a temporary, summery change. Do you think that a mixture of 3/4 7KG and 1/4 8K will come out too dark? What is your experience with Goldwell Soft Color? What should I do? Please help me!
Thank you!
Attached Thumbnails
Copper semi-perm (Goldwell Soft Color) on slightly bleached hair - please help!-emma-stone-easy-.jpg   Copper semi-perm (Goldwell Soft Color) on slightly bleached hair - please help!-emmastone2.jpg