Wish,
Why don't you do a practice shirt to try it out- If it comes out to the point that only you could appreciate it... Use it as a bed shirt! No big deal! It is all yours and no one has to "see" that it is not perfect! Personally, even though I am somewhat a perfectionist (I admit) I think anything that is not quite perfect is best- It says I made it! All for love peoples!

Plus... & this is an old crafters trick used in many different forms of crafting including sewing and such- When you "mess up" get some cording or rhinestones etc and affix around your design in various designs or just even around the border etc- Gives it an extra special touch, and no one else will be the wiser!
This tip is great even for those who have made shirts for awhile-
Ever set the iron too close to your "finished" design just to have it melt a small edge to "non-perfection"? Yeah- most have when multi tasking- Add a bow to that edge or again cording or ribbon all around the border, or even an extra special patch to that area that compliments the design- Really easy ways to "fix" mistakes and blunders! Relax and go with it!