I use a common tool for autoposting 80-90 "Summary Large Image" twitter cards per day and I follow less than 50 people per day with a ton of filters on the follow bot. I don't unfollow as I believe this is the most obvious spam metric. A legitimate user might follow a lot of accounts, but then turning right around and unfollowing those accounts is really obvious. I never like, retweet or auto-comment with the bot because it will invariably interact with spam. I manually comment on tweets to make it appear to their staff that the account is not completely on autopilot. Even so, my bot score is 39% probability of complete automation. I ran the tool on my followers and found that some of them are scored in the 80%-90% bot probability. Accounts like this will be the first to go.
Another thing to consider is that the botometer probably doesn't know how many people you've followed/unfollowed during the lifetime of the account, nor does it know which IPs you are using to connect. These metrics could push the botometer much higher.
I do not know what "network" means, but it might mean that you are receiving a lot of likes and retweets from the same accounts over and over again or that your accounts follows a lot of low-quality accounts. Run botometer on your own followers and block some of the obvious bots. Wait a few weeks then check your score again. Also, check who you are following and unfollow any obvious bots. You should also find some accounts with really great botometer scores and try to emulate their metrics. Certain ratios of likes, comments and retweets etc..
If you are a bot account and you're highly active, you're going to rank high on the some of the metrics no matter what you do. I think 2.5 might be unrealistic, but I believe that improving your scores overall would be wise. You don't have to be perfect, just not obvious. Twitter is clearly taking steps to kill bots and engagement spam. I heard on "The View" on ABC American TV this morning that Twitter announced that they will be deleting accounts with fake followers.