Yes, ranged attacks from spells are typically considered to be "weapon-like". This is definitely true of rays (and almost all ranged touch attack spells are rays) since from the rules:
You aim a ray as if using a ranged weapon
The rules further clarify that rays function as weapons for several other purposes, and the FAQ makes this very explicit:
Do rays count as weapons for the purpose of spells and effects that affect weapons?
Yes [...] rays are treated as weapons, whether they're from spells, a monster ability, a class ability, or some other source
The same rule applies to weapon-like spells such as flame blade, mage's sword, and spiritual weapon--effects that affect weapons work on these spells.
Most ranged touch attacks which aren't rays are things like acid splash -- spells where you actually throw or aim a physical object. Those are even more "weapon-like" than rays, so it's probably simplest to say all ranged touch attacks work like this.
There's another FAQ that indicates you can take "Weapon Focus (ray)" and the like; strictly speaking I guess those wouldn't apply to orb spells like acid splash.
This is all following the precedent set by 3.5; in Complete Arcane it specifies that rays and touch attack spells are "weapon-like" and thus interact with feats in the same way that other weapons do, with a split between ranged/melee type spells.
The RAW doesn't specifically say.
As you note in your research, none of the rules related to hitting objects have any information about what to do if the object is attended.
That said, you can use existing rules to figure out a reasonable alternative. The rules for smashing an object that you link say:
An object's Armor Class is equal to 10 + its size modifier (see Table: Size and Armor Class of Objects) + its Dexterity modifier.
If you try to use the spell rusting grasp on someone's armor:
You may employ rusting grasp in combat with a successful melee touch attack. Rusting grasp used in this way instantaneously destroys 1d6 points of AC gained from metal armor (to the maximum amount of protection the armor offers) through corrosion.
You can similarly touch a weapon with rusting grasp:
Weapons in use by an opponent targeted by the spell are more difficult to grasp. You must succeed on a melee touch attack against the weapon. A metal weapon that is hit is destroyed. Striking at an opponent's weapon provokes an attack of opportunity. Also, you must touch the weapon and not the other way around.
It says that weapons are harder to grasp, but it doesn't actually give any rules for how you should determine the AC of the weapon.
With this in mind, one reasonable ruling would be to apply this rule to attacks against attended objects, but let the object use the attending character's Dex bonus instead of its own, as well as any other modifiers that the character has that apply to touch attacks, like deflection bonuses or a monk's Wisdom to AC. If you try to touch an attended weapon, you provoke an attack of opportunity. This means that it's a little bit harder to hit an object that a character is attending than it is to hit the character, since most objects are smaller than their users.
Another reasonable ruling would be to say that it's a Combat Maneuver, like any other. In this case, I'd say that touching an object that's being attended by another creature would work like Sunder. In this case, you'd simply make a CMB check against your opponent's CMD, provoking an AoO if you don't have Improved Sunder. The drawback of this approach is it means that it's basically impossible for casters to touch an object being attended by a creature except at very low levels, since the CMB of a caster goes up very slowly, but the CMD of most other creatures goes up very quickly.
Best Answer
You are probably looking at a ray spell. The Magic rules state:
Other ranged spells will state whether it's a ranged attack or a ranged touch attack, which determines whether you are trying to hit the enemy's normal AC or their touch AC. In any event, it is a ranged attack and therefore the Combat rules state:
Unless you have a special ability that says otherwise, you do not add anything to damage. See Damage in the Combat rules - it says you add Strength bonus to melee or thrown weapons, period.
Though you should add more context to your question - just in case you're super confused, let me clarify that you don't need to roll to hit on any spell just because it has a range. Take Fireball, range Long. You don't roll to hit with it, you just place the 20' radius spread area wherever you want within that range (that you have line of effect to yadda yadda) and it affects everyone in that area.