Take the lane when you have to, but avoid delaying traffic as much as humanly possible. Do that by taking the shoulder when it's wide enough for cars to safely pass you and taking the MUP as much as possible. The sidewalk is out, unless you are willing to walk, nor ride, the bike along it.

Absolutely be high-viz. Multiple taillights (you can buy cheap lots on eBay and build a "large array" of blinkies) dorky neon yellow jacket, the works. None of this is expensive if you shop around.