Movin' on up to 2nd level spells...starting again with the cleric list.
1. Bless: There aren't many real stinkers in the B/X spell lists, but this spell surely is one of them. +1 to morale (which doesn't affect player characters at all), +1 to hit (which only makes a difference on one roll in 20), and +1 to damage (slightly more impact than the other components, but pretty lame for a spell that you have to be 4th level to cast.)
The spell description states that, at the DM's discretion, it may also be used for ceremonies of blessing or cleansing. Those aren't situations that come up frequently during adventures, in my experience, and there would have to be some in-game consequences for failing to use the spell.
The reverse of the spell, Blight, is if anything even more useless. It imposes penalties of the same magnitude as the normal spell's bonuses. Like the normal spell, all creatures to be affected must be within a 20' x 20' space. At least you can get the whole party together to bless them all. Good luck getting the enemies to cooperate and clump together to be blighted.
I have a few ideas for rehabilitating Bless into something useful, but since this series is about spells in the rules-as-written, I'll save those thoughts for another post.
2. Find Traps: Here's a useful one. It overlaps the thief's Find Traps ability a little, but that's really not a problem. It reveals only the location of the trap with a blue glow for all to see, but not the type of trap or how to disarm it. It lasts for 2 turns, so the cleric could scan about two rooms, or as much corridor as she can traverse in that time.
Despite the shared name, the spell and the thief ability are very different in key ways. The spell requires the expenditure of a precious spell slot, but it's automatic and tells you at a glance where the traps are; the thief ability is an unlimited resource but is uncertain and takes a full turn to search. (It's a common practice in old school games to allow anyone to detect area traps such as pits, falling blocks, or scything blades, as opposed to small traps on specific objects like the needle in the lock of a treasure chest. Generally this still takes about a turn of game time.)
The Find Traps spell is great when time constraints make searching for traps impractical, such as during pursuit, or when you suspect a gauntlet of traps and searching for them one at a time would be tedious and dangerous. Although it doesn't automatically tell you the type of trap, it does highlight its location for everyone, including the party thief. It seems reasonable that once a thief knows that there is a trap and where it is, he can probably figure out pretty quickly what type it is and either tell the party how to avoid it or attempt to disarm it without making his own roll to find it. Thus, cleric and thief can actually work in harmony, with the cleric's spell augmenting rather than supplanting the thief's role of dealing with traps.
There is one potential point of ambiguity in the spell description. It seems fairly safe to assume that the spell highlights the general area of a trap, not its specific parts, because that would tend to identify the type of trap. So, especially in the case of traps in which the trigger is located at some distance from the "kill zone," which does it detect? One or the other, or both?
3. Know Alignment: The relevance and usefulness of this spell depends heavily on what alignments actually mean in your campaign. If Law and Chaos are cosmic forces that are at war with each other, then knowing which one a person or creature sides with might be of great importance. Similarly, if Chaos generally tends toward evil and Law toward good, it's effectively a more powerful version of Detect Evil, since it doesn't depend on the target having immediate evil intentions. On the other hand, if Law and Chaos only represent behavioral tendencies toward stability and reliability, or toward fickleness and capriciousness, it's not really telling you anything that you couldn't learn from simple observation of the creature's behavior.
It can also tell you the alignment of an enchanted item or area, such as a sword or a temple. What exactly it means for a non-sentient entity to have an alignment is less clear, and probably something for the DM to determine in his or her campaign.
4. Hold Person: This is one of those spells that can change the entire complexion of an encounter in one fell swoop. It has a range of 180', at least as good as most missile weapons, so you can potentially strike down opponents long before they can engage the caster in melee. With a duration of 9 turns you don't have to worry about the affected creatures for a good long while. It can be cast at a group, affecting 1d4 creatures at normal chances to save, or focused on a single target for a saving throw penalty of -2. That's a meaningful tactical choice; neither option is obviously superior in most situations, let alone in every situation. You could cast it at a group and only affect one creature anyway. You could cast it at a single opponent and it makes its save despite the penalty.
The spell description specifies that it only affects humans, demihumans, and humanoid creatures, and also that it doesn't affect undead or creatures larger than an ogre (thus giants and trolls are immune.) The restriction based directly on physical size rather than using HD as a rough proxy for size leaves no question that human and demihuman PCs and NPCs of all levels are vulnerable. Since saving throws improve much more slowly than hp totals, this is a good spell to neutralize tough human and demihuman opponents quickly. Almost needless to say, it's non-lethal, so it's perfect for pacificst or semi-pacifist clerics, and for any time the party wants to take its opponents alive.