Your credentials and achievements are excellent, and you’ll do well at any school. You should be proud of your hard work, and I’m sure you’re looking forward to the challenges, opportunities, and excitement of college.
The issue is that deferred applicants at Harvard have a low chance of admission, about 2-3%, similar to that of other RD applicants. The Harvard applicant pool is so deep and wide that you’re likely considered to be “usual strong” or “standard strong” – meaning great, but not especially competitive for them. For Harvard, some of your stats are above average, and others (Subject tests) are below. Your ECs are average among applicants.
No one else can answer whether the risk is worth it. You need to ask yourself whether you’d give up a great shot (ED2) at Tufts for a tiny chance at Harvard and a reduced (RD) chance at Tufts. If Harvard is your dream school and you’d be settling for Tufts and you’d always regret not trying for Harvard, then go for it. If you think you’d be thrilled with Tufts (even if you might occasionally wonder about Harvard for a second or two before putting it out of your mind), then apply ED2.
In any case, make sure that you have a few likely schools that you’d love. In Boston, these might include Brandeis, BU, and possibly BC, but you’d have to investigate further to see which ones are good fits. And if you decide to apply to Tufts RD and get in, but you don’t get into Harvard, then dive in and don’t look back.