1. yes
2. most of the links should point to the homepage in order to build up the authority of your domain, and when you see certain pages stabilizing in the SERPs (say, on page 2 or 3 of google) you will want to boost the rankings of those pages, and to do that you will point high quality backlinks to them until they get at least to page 1. Once they're on page 1 you will have to analyze your page and competition again and see how you can push the rankings to top 3 spots, where most of the traffic is. This means you might have to do better on-page SEO, or get even more backlinks to those inner pages, or both. But you will figure this out when the right time comes
3. depends on the competition of your keywords. If you've done your keyword research properly you won't need a single backlink to rank. You just need to post content regularly (once a day if possible, if not then once a week at least, the more often the better obviously).
But anyway, if those $10 guest posts come from relevant sites in your niche and - more importantly - if they get traffic from google, they are worth the money. Probably even more than $10. Guest posts that cost $100 might obviously be better (they can still be scam, though, so you have to do your research), but many times a single guest post won't be enough to move your website not even one spot in the rankings. That's why targeting easy to rank keywords is so important. Well, until you build up your website's authority anyway, after that you can chase after keywords with higher competition
4. I wouldn't buy more than 4-5 backlinks at first. Do this for a few months (say 2-3 months), then increase the number of backlinks by 50-60% for 2-3 more months, then increase again for 2-3 more months and so on until you start ranking.
But the crucial thing here is that you keep building backlinks WHILE posting content. If you post content without getting backlinks is OK, but if you get backlinks without posting fresh content regularly it's NOT ok
And when you start ranking but - more importantly - stabilize in the SERPs you can reassess your backlinking strategy
5. VERY IMPORTANT! Spammed anchor texts are one of the most important reasons new sites never rank in google. That's why you need to vary the anchor texts like a madman. If your domain name is brandable (short + catchy + relevant, or any 2 combinations of these 3) many of your anchor texts will be the brand, while the other anchor texts will be your website's URL, generic terms (click here, visit us, our website, this page, visit our blog, this website, check us out today, read more about it here, etc.), or partially matched keywords. I wouldn't use more than 10% of the exact keywords as anchor texts, around 5% actually
NOTE: while do follow links are the best, getting some no follow links is highly recommended because it makes your backlinking profile look natural to the retarded googlebot. So, do not only get do follow backlinks, but no follow, too. And make sure you also get image backlinks, too, not just plain text backlinks. It helps even more
