Yeah with an aged account, solid karma, and a subreddit you've built over time, you're already way safer than most. Dropping a link every 10 posts sounds totally fine, especially if it’s not always to the same domain or formatted the same way. What usually triggers flags is back-to-back linking or patterns that feel automated.
To stay clean, just mix in real content regularly, switch up how you share links, and avoid pushing purely promotional stuff too often, unless it truly brings value to your subreddit.