Unique article writing and keyword density

Hello there , I'm planing to start my career as an affiliate marketer and im starting from scrach. There are fiew questions I'd like to ask about "inside" and "outside" seo and unique article writing . this may be not the place to post this thread , but as I mentioned earlyer im starting from scrash so I'll start with blogger bloggs to promote some of affiliate offers or wordpress blogs that are free . I haven't setteled yet on wich one to choose , currently I'm using blogger , I find it simpler (if it's even a word) . I made a thread before asking about whitch one is better and I got different opionions as well as if its possible to rank blog to rank 1 . I'll be doing everything manually building and optimising blog , writing articles and building links . Is that all that makes SEO ?

1. Is keyword density still a "thing" or something that you can use for youtube ?
2. Is warriaty of links better than lets say only building links on mini-sites or blog guest posting ? (by the way what is that ? blog guest posting . )
3.Could anyone describe to me what meaning has press release and what is that ? what does that do for SEO ?

I'm still a rookie at this , everything looks so difficult and confusing but I'm going to figure this out . I'm learning alot about IM and SEO . I'm not going to quit , it all looks interesting and fun if you can call it that and i beleave it's a better thing than wasting time on useless video games that I've been going for last 10 years I believe.

try 5-8%

take 2% and add LSI Keywords

try here, AnySend will give you best payout

according to current strategy i guess 1% keyword density is preferable.
guest posting is nothing but you can write a content about your site and can post them in other's site with a link to your site

Well there are lots of rumors about keyword density, but what makes your site rank in Google are mostly links. For keywords density may be repeat once or twice the keywords in a 300 word article will be good.

I would suggest looking into LSI keyword-focused articles.