Perfecting My Porter

Hey guys, hope everyone is doing great.....

I have question that I hope you all can help me with... I am on my second batch of beer, this one actually came out 1 million times better than the first.... On this batch, I made a vanilla coffee porter. I used a mixed grain, malt kit from Homebrewing. It was the Brewers Best Coffee Porter kit. The only thing I did different from this kit was add the vanilla beans to my secondary. To get you to where I need my question answered here was my process....

The cook turned out great, put the beer in a primary for 10 days, in a temperature controlled refrigerator at 68 degrees. Then I put it in a secondary for another 14 days. Once the secondary was complete, (didn't see too much action in the secondary as far as gassing) I bottled using the priming sugar provided ( 3.5 oz for 5 gallon batch) allowing for 14 days for conditioning in the same temperature. On the 14th day, I tested one and felt it needed a few more days of conditioning (not enough carbonation), I did raise the temp a few degrees to 70 to 71 degrees. After a total of 18 days of conditioning I tested another with much better results. At this point I dropped the temp to 52 degrees to drink. The beer tasted great, you smelled the vanilla tones, along with the coffee. The flavor was right on, no off flavors nor did it have any weird smell or anything. (abv +/- 4.4%) The carbonation in my opinion could have been a little more, but I don't know. On the pour, you didn't get a lot of head, a couple of bottles poured flat while another poured with some head, nothing lacey. The beer did not taste flat at all, in fact it tasted as it had enough carbonation. In my opinion, I really like the way it came out.

This is where I think I need improvements and I hope you can add to it based on the info I have provided. 1. ferment in a warmer temp. like 71 to 73 degrees... 2. Add a little more sugar on the priming (Hoping to get better carbonation) 3. Would like to add more vanilla to get more of that flavor out. 4. I'd like more ABV, but don't know how! 5. I'd like a more lacey and lasting head on the pour.

So here is my question for you pros out there.....
1. I am a firefighter and have been the fire house chef for a few years now. It is in my nature to always want to try something new. Making beer I know is a little of the same, but very different. My question is, should I continue to make this type of beer and perfect it, or continue on my character trait and try something new?
2. Based on the information provided above, where do you think I could have improved on?
3. How many different types of beers do you guys make and how often? Do you stick to one style or do you experiment with different styles?

The reason why I ask this is because, at what point do you pick a beer and just keep doing it? I use to be that guy that only drank Heineken all the time, then the world of beer opened my eyes to a plethora of possibilities. I go to a bar and I never order the same beer twice, I go to world of beer and have yet to repeat the same beer, I go to the store and buy a 6 pack of all different types of beers.

Your help is greatly appreciated and sorry for being long winded on this.