1) Bounty hunting is a profitable part of the game and one that I find most fun. But I'm trying to figure out the ammount of "hit points" each ship class has but it appears to be random:

First bounty: Walnut class, killed by a single M-12 Torpedo, rewarded 3500 credits.
Second bounty: Shark class, ate three M-12 Torpedos and an E-10 (wich is EMP, but I just fired everything), rewarded 4300 credits.
Thired bounty: Walnut class, this time the Walnut class took three M-12 torpedos before perishing, rewarded 2100 credits.

2) I read a post here where someone was complimenting the game's music, but I've never heard so much as a single note. Was the poster complimenting the silence or is there a "Toggle Music" button somewhere?

The music control panel is located within the bridge view, as seen in the attached screenshot.

I am unable to answer your first question, as I have never used torpedoes (in countless hours of gameplay).

However, I can offer some data (acquired through observation of far-off battles, as well as the usage of my point defense laser) from DebugLog_Game.txt: For further study, the aforementioned file can be found within the following directory structure (depending upon your installation location choice):
C:\Objects_in_Space\ObjectsInSpace\log\DebugLog_Game.txt

Or, for Linux (location remains static):
"$HOME/Documents/ObjectsInSpace/log/DebugLog_Game.txt"

Nice! Thanks for the info!

According to the log the first torpedo destroys the target vessel with 120+ damage, but it's like the game doesn't remove it from the game until it's been destroyed three times. I noticed this yesterday that after the first torpedo hit, I got paid for the bounty, but the pirate was still going strong (running through hazards and heading out of the system).

[22:13:32] [DETAIL]: Torpedo: PINGING! Ping timer = 0.672433
[22:13:32] [GAME]: Torpedo: Beginning rotation to 183.958725, difference 1.684769.
[22:13:32] [AI]: Torpedo: Triggering explosive due to proximity to Red Storm
[22:13:32] [AI]: Torpedo: Triggering my warhead.
[22:13:32] [GAME]: Vessel 'Red Storm' was hit by Explosive at 102.60, 200.26
[22:13:32] [GAME]: Modified strength is 134.520462
[22:13:32] [GAME]: Ship's pre-damage state is 100 percent, with 16/16 modules working.
[22:13:32] [GAME]: Red Storm: TAKING 134.520462 damage of type Explosive
[22:13:32] [GAME]: Red Storm: Applying a max of 134.520462 Explosive damage to hull location 'Stern'
[22:13:32] [GAME]: Red Storm: Hull damage: 80/80
[22:13:32] [GAME]: HULL SECTION DESTROYED.
[22:13:32] [GAME]: Destroying all modules contained in this section...
[22:13:32] [GAME]: Red Storm: Removing ALL modules.
[22:13:32] [GAME]: Red Storm: Valid modules to damage: 2.
[22:13:32] [DETAIL]: Red Storm: Disconnected module 'GX-ONE'
[22:13:32] [DETAIL]: Red Storm: Disconnected module 'DVJD-400'
[22:13:32] [GAME]: Red Storm: I have just been disabled.
[22:13:32] [GAME]: Bounty complete on vessel Red Storm
[22:13:32] [GAME]: Ship's post-damage state is 100 percent, with 14/14 modules working.
[22:13:32] [GAME]: Damage done.

....

[22:13:34] [DETAIL]: Torpedo: PINGING! Ping timer = 0.630953
[22:13:34] [DETAIL]: Torpedo: PINGING! Ping timer = 0.603426
[22:13:35] [GAME]: Torpedo: Beginning rotation to 189.803543, difference 0.354904.
[22:13:35] [AI]: Torpedo: Triggering explosive due to proximity to Red Storm
[22:13:35] [AI]: Torpedo: Triggering my warhead.
[22:13:35] [GAME]: Vessel 'Red Storm' was hit by Explosive at 102.08, 196.85
[22:13:35] [GAME]: Modified strength is 122.686684
[22:13:35] [GAME]: Ship's pre-damage state is 100 percent, with 14/14 modules working.
[22:13:35] [GAME]: Red Storm: TAKING 122.686684 damage of type Explosive
[22:13:35] [GAME]: Red Storm: Unable to apply damage, no hull locations from this angle left undamaged.
[22:13:35] [GAME]: Ship's post-damage state is 100 percent, with 14/14 modules working.
[22:13:35] [GAME]: Damage done.

....

And finally:

[22:13:37] [GAME]: Torpedo: Beginning rotation to 184.043152, difference 1.945770.
[22:13:37] [AI]: Torpedo: Triggering explosive due to proximity to Red Storm
[22:13:37] [AI]: Torpedo: Triggering my warhead.
[22:13:37] [GAME]: Vessel 'Red Storm' was hit by Explosive at 101.63, 193.95
[22:13:37] [GAME]: Modified strength is 123.741318
[22:13:37] [GAME]: Ship's pre-damage state is 100 percent, with 14/14 modules working.
[22:13:37] [GAME]: Red Storm: TAKING 123.741318 damage of type Explosive
[22:13:37] [GAME]: Red Storm: Applying a max of 123.741318 Explosive damage to hull location 'Bow'
[22:13:37] [GAME]: Red Storm: Hull damage: 90/90
[22:13:37] [GAME]: HULL SECTION DESTROYED.
[22:13:37] [GAME]: Destroying all modules contained in this section...
[22:13:37] [GAME]: Red Storm: Removing ALL modules.
[22:13:37] [GAME]: Red Storm: Valid modules to damage: 10.
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'R100'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'R100'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'R100'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'R100'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'CNM/1'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'C5-SNS'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'C-HLM1'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'RCSYS-2'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'AE-35'
[22:13:37] [DETAIL]: Red Storm: Disconnected module 'SPL-7'
[22:13:37] [DETAIL]: New Sensor Object with ID: 30
[22:13:37] [DETAIL]: Mauna Kea: added explosion sensor data (30) instance at 101.629967, 193.947739
[22:13:37] [WORLD]: Vessel destroyed and needs to be removed: Torpedo
[22:13:37] [GAME]: REMOVING Torpedo from sector PUP-230
[22:13:37] [DETAIL]: Removing sensor data for ship 'Torpedo' from ship Mauna Kea
[22:13:37] [DETAIL]: Removing sensor data for ship 'Torpedo' from ship Red Storm
[22:13:37] [DETAIL]: Removing sensor data for ship 'Torpedo' from ship pirate
[22:13:37] [WORLD]: Torpedo: deleting object.
[22:13:37] [WORLD]: Vessel destroyed and needs to be removed: Red Storm
[22:13:37] [GAME]: REMOVING Red Storm from sector PUP-230

It's definitely a bug. :/

Edit:
P.S. Oh, what a fancy ship you have! Which one is it? I've seen only like three or four different models for sale but I haven't seen the benefits of buying any of them. What drove you to going for a new ship?

Cool! Maybe I'll try a new ship, if only for the cool interior and change of scenery. The speed difference from 1.1 to 1.3 is 15% but since I'm at 1.2 I definitely won't feel any difference going either way.

I haven't quite figured out the trading yet but bounties are easy (if all your pods are empty) and give about 10.000 credits per hour of gaming. Sad thing is that the pirates don't even defend themselves if I'm not carrying any cargo, so to put a little excitement into this I buy something like a random can of gas before I head out to get them interested. But I imagine dealing with a certain contraband at certain terminals could yield much more.

The thing I've been struggling with regarding legitimate trading is that the terminals have such limited quantities of each comodity. Even when buying everything they have of everything, I would just fill up maybe six cargo pods.

I saw a Ceres Mk II for sale as well. I didn't buy it, since it seemed to be the same as a Ceres Mk III with only 4 pods.

That reminds me... at one station, I did notice that a few had varying amounts of maximum pod capacity (lower than the norm), but, I did not take notice of the class names. Just as you, I had completely disregarded them.

Is this a recent addition? It seems that it might have only began occurring as of the last few updates, though, perhaps not.