Review on last night's dinner

Last night I made Split, Stuffed, Baked Chicken with a Mexican influenced salad of Sweet Potatoes, Caramelized Onions and Guajillo Chile Dressing, and Slow Cooked Cranberry Beans. The main dish was Fall poultry comfort food, the rest was Southern Mexican. Not exactly the same 'flavor profile' but it was fine.
Everything turned out OK, but there were definitely challenges. Namely: timing. Knowing when the chicken is done and being able to estimate when everything will reach the table.
One factor that needs to be addressed is the temperature in my oven. Maybe it's time for a new oven thermometer. Recognizing that in the past I would often cook too hot, I now am so careful that it seems to take forever. I keep opening the oven, checking, putting it back in, wondering if the temperature will catch up during rest, setting my timer for another 10 minutes, watching the golden light brown color darken and darken, wondering when we'll eat, and when to reheat the other dishes that have been ready, wishing I hadn't dressed the salad yet... It still seems like so much guess work! I'm thinking that with properly calibrated tools, I will have a better timeframe and smoother transition from oven to plate.
My next point: I need to make and remake the same thing to master it. Otherwise each dish will always be a crapshoot and I'll have gained little knowledge and continue to over/undercook. I don't think I'll make the exact same chicken as last night, but I'll still do a whole chicken, perhaps an easier version from class where you just rough chop lemon, garlic and herb sprigs and throw them into the cavity. How easy is that? Then make a sauce from the drippings. OR maybe brining will become my signature, go-to move where I attain perfect, effortless results. 
Side note on the two Mexican dishes I made from Rick Bayless' book, they were fantastic. I love the way he gives you Riffs to change it up or add to the dish. These may become signature dishes too.