Some keywords ranked, some not

I have website and I am tracking 5 keywords. It is typical black hat hack website. Problem is that 2 of these 5 keywords are ranked in top100, 3 of them not in top100. That 2 which are ranked have another 'main word' than 3 which are not ranked. I don't think that is over optimalisation, maybe is a little too much keyword density (0.97%) but I saw websites with ~1,50%. I think these keywords should be now like in ~top60. My website is 1,5 month old. Should I just start creating backlinks or still waiting? Any ideas?

Your keyword density is perfect. So no problem with that.You can start creating backlinks mate. Get good quality backlinks by targeting all your keywords. Within a month you can see the improvements in ranking.

More competitive keywords would require some links before they break into the first 10 pages.