UFO Sanae-B: additional info on focused vs unfocused shot. Some of this is counter-intuitive.
Except at a power level of one (PL1), the unfocused shot will kill stage enemies more quickly than the focused shot. At PL2-4, the only possible utility of the focused shot during a stage (excluding the midboss) would be in firing at a distance at a concentrated group of non-popcorn enemies; depending upon PL, the splash damage from the frogs might kill the group more quickly. The focused shot is still the better distance shot against bosses, although the unfocused shot (for PL2-4) would likely be better whenever the boss is moving quickly. It's also important to note the severe drop-off in power (for PL2-4) when not properly aligned beneath the boss (I'll estimate the wiggle room to be 15 pixels on either side, but I'll also be damned if that's accurate).
Here's why. Except at PL1, the unfocused base shot is more powerful than the focused base shot (base shot = no frogs). Additionally, because there is a delay between the impact of a frog and the point at which all damage from a frog has been dealt, it takes several seconds for the frog-damage of the focused shot to catch up and make the focused shot more powerful than the unfocused shot. For PL1: the shot data supports the theory that it's the base shot, not the frog-stream, that has an increased power when focused. Compared to the focused shot at PL2-4, the focused shot at PL1 is more effective against stage enemies and less effective against bosses, which is the same thing that happens with the unfocused base shot. It's also worth noting that the unfocused base shot does the same amount of damage at all PLs. It's impossible to determine this for the focused base shot because the number of frog-streams changes, because some frog-streams do more damage than others, and (to a lesser extent) because total frog damage is at least somewhat dependent upon impact location.
Below are the three experiments that back up that info.
The first test was on stage three's opening fairy: a robust, non-popcorn enemy. I'm fairly certain that there aren't any stage enemies with either a larger health bar or a larger hitbox, so the results here should apply to all stage enemies. Keeping the same, initial vertical position, I positioned myself directly under the fairy's entrance point and held down the fire button. [Originally I did this with stage practice (for PL2) and with continues (for PL4), and I was later able to extend this to PL1 and PL3 with a power-level hack*.] For PL2-4, the unfocused shot killed the fairy more quickly than the focused shot. I tried this at a slight offset, which made it so an additional frog was impacting the fairy**, but there wasn't any noticeable difference. The fairy only got off five center bullets when I used the unfocused shot (for PL1-4), and it got off its full volley of eight when I used the focused shot (for PL2-4). Against the focused shot at PL1, however, the fairy only got off three bullets. So, the effectiveness of shots against single stage enemies goes like this: PL1 focused > PL1-4 unfocused > PL2-4 focused (roughly similar).
The second test was a crude way to verify the results of PL1 and to ensure that there weren't any shenanigans with the power-level hack. After the stage name appears on the first stage, a fairy appears from the top-left side of the screen. Without running the hack program, I killed the fairy once while unfocused and once while focused. Watching the replays, the fairy survived longer - it made it farther down the screen - against the unfocused shot (at PL1). So the focused shot was definitely more powerful at PL1.
The third test was against Ichirin's midboss spell card at each power level, using an invincibility hack* (and, later, the power-level hack). With only one (slight) exception, the focused shot resulted in a quicker capture time at all power levels. The unfocused shot had a consistent capture time at all power levels of exactly 19.94 seconds. I tested the focused shot in two places: directly beneath the boss and slightly offset. Note that there isn't an offset at PL1 because the frog is in the center of the shot.
Focused capture times (PL#... centered # frogs, centered capture time [in seconds] - offset # frogs, offset capture time [in seconds]):
4... 4, 12.9 - 3, 17.2
3... 3, 12.9 - 2, 18.3
2... 2, 13.4 - 1, 20.5
1... 1, 14.5 - 1, 14.5
[unfocused: 19.96 seconds]
These are averages of two attempts. Largest differences between similar tests: .5 seconds for offset focused and .3 seconds for centered focused (and 0 seconds for unfocused). The differences were usually half of those values. I ran a third test for the largest difference in both centered and offset, and each third value fell between the appropriate, existing values. The ostensible explanation for the differences is that there's a random element in determining the placement of each frog's splashes, and the variability would be further exaggerated by an imprecise horizontal offset (I just made sure the right number of things were hitting, so it's very possible that I was a few pixels off between attempts and that this slightly affected the results). The focused capture times roughly align with the previously given data table on distance shot power.
Side note: I'm not going to test the other shot types. For some time I've had the feeling that S-B killed enemies more quickly when unfocused (and now I know when and why), but I've never had this feeling with other shot-types, so I don't have a reason to test the others.
*thanks due to SupremeBogus for hooking me up with this.
**number of frogs that impacted the fairy for PL2,PL2,PL4: 0,1,2 when centered; 1,2,3 when offset.
edit: incorporated updates stemming from being able to use Bogus' power-level hack; most notable update is the power-level-one nonsense. edit2: made slightly less wordy. edit3 (dec): clearer explanation of power-level-one nonsense.