
i think the options are unlocked just on number of hours played. also possible number of 1CC's. i've only clocked maybe 5 hours practice on saturn mode, and over a hundred on arcade mode. but i think i had all four options when around 50 hours practice
the dogs don't really do much, you just have a dog rating in your options meter. collect them all in saturn mode and you get "Pro Breeder" rating, or something

for the C shot, it is 16 hits, ie pressing the button 8 times, and both shots hitting. HOWEVER, they cannot leave the screen, and they can't "self-destruct". that is to say, they explode when you release the button. they must make the explosion from contact with an enemy. perhaps you sometimes miss a 10k weapon bonus because you tap the button, or something similar. if using the C shot on 1 large enemy, you want to be as close as possible to minimise this. so if a large enemy takes 4 hits from the C button to die (ie to shoot twice), it is best to press and HOLD the C button until 4 hits have exploded, then release the button. so the C button is very sensitive to timing

the Z button is for 15 seconds locked on, and is one of the easier weapons to get bonuses from. again, this is total 15 seconds, ie 7.5 with each laser. as the laser becomes more powerful when Z button is held down, best technique is to tap the Z button, to keep the enemy/boss alive for longer, to have better chance of making weapon bonuses.
weapon levels are related to score from using that particular button. mainly this is chains, but does include weapon bonuses. even collecting dogs will help level up your X button (ie B and C levels).
hope this helps
