It's not your decision as to whether or not your emails get blocked as spam, because spammers would use the same mechanism to say "Our messages aren't spam either, honest, all these people asked for penis extension pill information, really they did, even that 11 year old boy and that 88 year old woman, honest!".
There are essentially 3 reasons why a message might get identified as spam, and you need to look into all of these if you're not using an established bulk email service:
"It looks like spam" - some emails contain certain phrases that trigger anti-spam software that looks at the content of messages. You need to make sure your emails don't contain any (or at least, too many) of these triggers. Not that you'll find a published list anywhere. Also there are various things (DKIM, etc) that are important for senders of bulk email, and not having these or having them set up wrongly will increase your chances of having automated filters classing your emails as spam. You mention that you've taken care of the technology side of things here, which is great, but I think ultimately futile because of my 2nd reason.
"It comes from a spam haven" - some IP addresses are listed either because of a past history of spam, or because the owner of those IP addresses doesn't have a good history when it comes to dealing with spammers, or because those email addresses shouldn't actually be sending email in the first place (e.g. dynamic IP ranges for ISPs, highly volatile ranges related to cloud providers whose providence its not possible to guarantee).
"It tastes like spam" - Lots of people say "I didn't ask for this!" and click the spam button / move it to the junk mail folder on their client, leading their provider to block any further messages. This is a real issue if you send to end users who are using webmail providers, because that can represent a lot of users, especially as many ISPs buy cloud email services for their customers from the likes of gmail, hotmail or yahoo these days.
There's a reason why Mail Chimp and similar services are expensive, and it isn't just because their owners like lighting cigars with ten dollar bills.