All true...
I understand the mindset of hitting big second serves... but unless you are going to win points outright is it worth the gamble. I can tell you for sure if you miss you are going lose the point outright.
If you opponent it teeing off on your second serve there is an easy solution, take a little off a few of your first serves and get a higher percentage in. Still use your big first serve as a deterent but manage your service percentage so you do not need to depend so much on your second serve to win you points.
...but now we're kind of into the realm of serve technique and tactics. Pancho Gonzalez used to say that you needed to get your shoulder into every serve, to put some sting into each and every serve you hit. Two summers ago, my coach had me working on a heavy, heavy kick serve. Not necessarily just for a second serve, but that's the first reason he wanted me to go there. What I found out was that in some ways, you actually hit a kick second serve
harder than you do a flat or slice first serve. You have to really go
after your serve at contact point, and this is especially true of kick second serves. Watch Samantha Stosur's second serve. If you don't go after a kick serve, it's going to fizzle and sit up...or maybe not even make it over the net or back down in the court.
My kick second serve, hit that way, has lots of clearance over the net and kicks up above most player's ideal hitting zones. I also use a kick serve on the first serve. What's the difference? On a kick first serve to the ad court, for example, I'm probably going to go for a very wide angle. If I can tag one there and move in, I've likely got an easy first volley to open up the court. On a second serve, same situation, I'll do a body serve, more or less straight down the middle of the box. Same kick, same clearance over the net, but a better probability of going in because I'm going down the center of the box. So you need good technique, and you need to go after your second serve...but unless you're trying for a second serve winner...and there are times you do this, as in down 4-5, 0-40 on your serve...you temporize the whole thing by not going for too much of an angle.