301 redirect to improve rankings? Will it work?

I would like to know, if I buy expired domains with great backlinkprofile and then 301 redirect them to my moneysite will that help me boost the SERP?

In this process is there then anything I need to have in mind?

1. Different hosts
2. Maybe the domain needs to be online and indexed before making the 301 redirect
3. Is it better to make the redirects to my tier 1 instead of the moneysite
4. Should I linkbuild to the redirected domain with related keywords
Etc..

I really don't understand how 301 Redirects work, in my opinion it's just a straight link from the domain to your website and that's it.

Yeah, my thoughts as well. Just a redirection, nothing more.

We may be wrong though, maybe it adds some link-juice or something but I don't think so.

I know for sure it works but I am not 100 % sure if one method is more valuable than another

301s work really great but there's a lot of research that goes into buying domains, more than 20 factors that you need to conider..

most people just look for pr, pa, da,tf, cf, link profile.. But There's much more to analyzing domains than these factors.

I know and I am very good finding these domains and I look at more then 20 factors, but can you help me with the questions I ask about if there is something I need to take into consideration when I have located the strong domains and need to set them up?