While not huge, a heavy is 300,000 lbs maximum certified takeoff weight or greater as opposed to just greater than 300,000.
Traffic information is very loose for VFR towers/Visual towers or even towers in general. Those with CTRDs may use traffic advisories, but traffic information given by visual references is really loose (and there is a difference between Traffic Advisories and Traffic Information).
Traffic information only says to describe the relative position in an easy to understand manner. That means you could say "Traffic, Baron on a left base" or "Traffic, Piper 3 mile final" etc. You aren't restricted to ahead and to your right. Or even "Traffic, Cessna Skylane departing runway 7L" (as opposed to extending downwind, give traffic information on departing aircraft so that the pilot will extend downwind and turn base for you.. telling an aircraft "extend downwind, I'll call your base" is a personal pet peeve of mine because efficient traffic flow can still be done with proper traffic information. You tell the pilots what is going on better too, so you can help them help you.).
As far as VFR aircraft entering the pattern, it is usually better practice to have them enter a specific leg as opposed to just "enter left traffic" so that you get a better idea on your picture. "N12345, enter left downwind runway 7L. Expect to follow Piper Cub turning crosswind." When they report the traffic in sight, you can then say "Follow that traffic".
Otherwise, nice job. Should come in handy for your controllers.