Rather than calculating power draws and alternator output, I like to have a volt meter on the dash. That way there is no guessing involved.
As Damocles points out, I did the calculations and determined that my gen2 should have about 100 Watts extra to power accessories. In Houston I don't have a need for much extra power, but over Thanksgiving I rode over the Continental Divide on the way to Las Vegas and passed through some freezing temperatures with snow on the sides of the road.
At 5,000 rpm with the high beam on and 80 Watts of heated vest and 20 Watts of heated grips the Volt meter still indicated 13.8 Volts. A nice thing on the gen2 is that if your Volt meter tells you that you need a little extra charging capacity, you can turn off the high beam and pickup 50 Watts when needed.
For dash lighting, I like LED lights that have an array of small elements pointing outward. This spreads the light out across the face of the instrument illuminating the whole face better. Also, they last longer and if one element burns out, you still have the other four working for you. I stick with the white ones.
Really need an ammeter to know whether you are consuming more than the alternator is producting. A voltmeter won’t tell you that directly. You might be able to infer it if you know at exactly what voltage reading your current draw goes negative.