Well you've just used up everyone's supply of question marks for the next 2 months. This isn't a Google Analytics question, which is why you're not getting a reply in the Google analytics forum. However, if you're looking for a tool to analyse your competitors backlinks, Caphyon's Advanced Link Manager is probably the best on the market.
You can always do site:domainname on yahoo to check back links. Nice if you have a low budget and can get you started.
The closest you are going to get (if I understand what you are asking for) is the Site Info from http://www.alexa.com
According to me there is no such tool which track accurate competitor traffics. But still Alexa helps you in tracking traffic of competitor sites.
Well you can do all the methods stated up but for sure nothing compares with WEBCEO I am not from WEBCEO , but I am using their software for a couple of years and I am very satisfied. Give it a try, they have also the free version that has lots of useful tools
I am also searching this kind of program who gives your far reliable facts and figures. I tried the alexa rank but so much trusted source.
In such a case, traffic analysis can be done by Alexa, though it's not the accurate one but if you are not the owner of the site then you can't have the traffic details of the site.
You can you Spyfu, alexa, quantcash. If you just wanna about backlink competitor, u can use yahoo siteexplorer. use linkdomain:site.com