I have website with long name and I use tinyurl ex. tinyurl.com/1234 if I promote website with tinyurl How SE collect my website information tinyurl.com/1234 or mydomain.com??
No SEO value but you can definitely use these type of services. Like i know one good site that converts long url into short - http://www.fly2.ws
Well, from my experience, redirect will affect your SERP, not that much but enough to do small harm. Also, if tinyurl.com decides to change it system, for any reason, and your tinyurl changes, all your SEO effort will be down the drain.