shiba inu adoption

Question
I recently adopted a shiba inu..she was not abused, the woman was allergic to her and she spent most of her time alone in a yard.  She has adapted really well and is becoming more socialized quickly.  

I have a few questions.  She is 5 yrs and was never spayed.  I have been reading online, but still don't feel like I have the best information to make a decision.  She is really playful (which I like..not too much) and very affectionate.  What are the pros and cons and is it better for her to be spayed at this age?  She does not roam alone, so I'm not worried about other dogs and I also do not plan to breed her.

My other questions have are behavioral.  She is very attached to me and I have some problems with separation anxiety.  She is getting better, but for example if I take her somewhere and have to leave her sight for anything she crys..and doesn't usually stop until I return.  I can see how anxious she gets.  She has also become much better at walking on a leash and with other dogs, but still can be skittish and nervous.  I am afraid sometimes when she is startled that she could bite.  I'd like to work with her on this and be able to train her well so that I could even take her on jobs with me and know that she would be calm enough to stay put and play on her own.  

Thanks for any advise!
Best,
Melissa

Answer
Well for health reasons,it is still a good idea to get her spayed,as an intact female is a lot more prone to breast cancer,also getting her spayed will eliminate uterine&ovarian cancers,as well as a deadly infection,pyrometrea,so getting her spayed now is a good idea

With separation anxiety what you can do,is just leave as little as 5-10 minutes and then build her up from that,and sometimes if you gradually leave for longer they will get used to it,also there is a natural product called 'rescue remedy' that you can give to dogs with just a drop on a  cracker or treat,but as a last resort some dogs do have to be given medications such as prozac but ONLY by a vet and as a last resort

As for her being skittish,Shibas tend to be like that,mine is still skittish after nine years,but what does help is to take her to obedience classes,it does help to get them used to things,and that is the best way to train a dog