The rate at which children pick words, and choose to speak them, varies greatly. I wouldn't worry too much about that.
My daughter, 14 months, will randomly walk into walls, fall down, etc. This is no big deal either. She just tries to get going too fast sometimes and can't stop herself. Has your daughter been trying to run?
I'm not sure about walking on tip toes, but I've noticed my daughter does it too sometimes.
About waving goodbye- My daugher also quit doing that after she did it for so long, but she is now moving on to master other skills, which waving goodbye definately is (a skill). Babies/kids will constantly work on something until they have it mastered and once that's accomplished, they may not do it in lieu of trying something new.
All in all, I would say it's all pretty normal. HOWEVER, please talk to her doctor. They are really the only ones who can say for sure. Like someone else said, try not to self-diagnose. I have worried myself sick something because of things I've read/heard.
Best of luck to you!