chem/stoo: I'll respond to these comments as best I can. chem, not entirely sure of all your meaning, so if you're ziggin and I'm zaggin please forgive.
Here is my take on head vs. chest voice, as I've been taught by instructors who handle pros, american idol winners, etc (guys who know about singing):
Everyone, male and female, has two basic "registers," based on where certain cavities or open space inside our upper bodies are located, which are available to bounce sound around in before exiting your body through your mouth. These are the chest and head registers. The chest register is easy to employ. It has one basic resonation chamber - the chest. You certainly do blend a little throat (larangial) in there, but it is easy because that is how you talk and it's second nature.
The head gets a lot trickier. Now you're dealing with a few different chambers and tapping in to them takes time, training, practice, patience, trial and error.
There is also a nominal third register called mixed voice. Really this is just tapping in to both chest and head resonance simultaneously.
So, about damaging the voice. Guys do it two common ways: trying to sing in chest voice too high (called "pulling chest") and trying to create distortion by tensing their throat. Other frequent methods of vocal damage include: poor breathing technique (dries the cords out), too much drinking and smoking (dries the cords out, among other things), lack of sleep and lack of practice (weak muscles) then trying something too challenging (which results in straining for notes, getting distortion improperly, yadda yadda).
About use of head and chest voice relative to my tone and grit and such: let me use the analogy of a guitar (and the guitarist). You have six strings, which we'll think of as different registers, since you get a lighter kind of tone as you play from the thicker to the thinner strings. For purposes of a perfect analogy the guitar would only have two strings, but whateva. Obviously the thickest string is going to be where you get the beefiest tone and some people are really gonna dig that tone. Some players are going to frequently chug rhythms down on it's first few frets and such. But that one string is only going to carry you so far up the potential note range of the guitar. You can play single string up to what, E3? Then you could start bending that string, if you wanted, and get a few more notes. Now that is a good example of pulling chest. You're at the maximum capability of that beefy register, but you're hell-bent on using it and strain for some notes your karaoke buddies are waiting for. If the guitarist keeps bending the string it will break and so will the voice. Fortunately, both can learn to utilize the next register. Guitarists learn to scale across all the strings and vocalists learn to tap in to those cavities up in the head. The better you do this, you can actually get a pretty substantial tone, with some edge. But it's always going to be lighter than chest tone. When a great guitarist is shredding on that thinnest e string, going meedly meedly meedly, no body complains that the tone isn't beefy enough (assuming the guitar is well-built with balanced tone). And that leads to the next point. Let's say our guitarist is really great at chugging on that low string and is ready for 11-gauge strings. But needs some work up top, so opts for 8-gauge there. Now there is potentially going to be a big difference in tone, from the bottom of the run to the top. So, partly where I'm at is building up power up top and in order to build one good voice all together, I have to lighten up a bit on bombast down low. A rule of thumb is you don't start so aggressive and thick down low that it's impossible to maintain a good, unbroken, unified voice from the extreme low your capable of to your extreme high.
Let's talk Bruce for a moment. If you listen to his Number of the Beast through Fear of the Dark tour recordings, you're going to hear a substantially thicker-toned Bruce than Brave New World through present. You're also going to hear huskiness, flatness and sharpness, note dodging - just a tired sound. Present Bruce has thinned out, but it still suits the music fine. He's very accurate, the tone is pleasant (that is subjective - to these ears there are more pleasant tones in the world and there are those who hate his voice, I'm sure, but it works for me.) I no longer cringe listening to Maiden shows, due to the singer sounding like he's getting beaten up in an alley. He's a strat now, not a les paul, but it's sustainable.
My opinion on Geddy is not that he over-utilized head range. Head range, if sung properly is pretty relaxing, pretty easy on the cords, takes less air (smaller opening). My opinion is that Geddy stopped practicing enough, drinks too much and sang too much challenging stuff under those conditions. I would bet "Big Money" that if he dedicated himself to vocal training again he could get very close to his former power and control. No, not the 2112 buzzsaw. That actually sounds like unhealthy distortion to me. But Permanent Waves edginess and control, yes.
Yes, Stoo, it is fair-enough to say my bandmates hear potential. To build up my voice the way I want (and think is best) should take 2 - 3 years. In the meantime it's a work in progress. But, it is also good enough for them, for now. Good enough, also, that some money-bags types who have hung out at rehearsals for months finally gave the ok for management to start booking better gigs and building sets. To have this guy who'd watch all our performances with folded arms, week after week, finally come up to me and say, "damn, you have improved incredibly in a very short period of time. You're sounding very good and we're ready for some real shows" felt amazing.
Chem, these three recordings are just my personal run-through. Band practice can be infrequent and I get bored of practicing Maiden songs, so I thought recording some rehearsal and getting a sense for what it really sounds and looks like would be of benefit and just more interesting to me, to give a good incentive to practice as much as I need to. I would say a bolder approach comes out on stage. If I over-do the aggression a bit and go a little hoarse, I can just lighten up practice for a few days and recover. That isn't how I want to personally rehearse though. That's a good way to encounter physical setbacks or permanent damage. Creating healthy distortion is pretty tricky. I'm workin on it, but it isn't my focus. I don't want to end up like Hetfield, who sounds like a mess.