Squires?

[Shlee]

There's no WoB that Lopen doesn't have a spren and is a squire, however: in-world WoR has it WR had squires; Dalinar saw a vision with a Radiant and men, who had no Shards who started to glow; Teft reported he saw 'several of the lads glowing' around the time Lopen inhaled the stromlight from the sphere; consciously inhaling stormlight has been done by all surgebinders so far after they were aware of their spren. 

The timing in WoR is also significant - Lopen and the bridge 4 men acquire this capability right after Kaladin says the third oath.  I personally think that that's indicative of them being squires. In addition, all the Radiants we have seen have interacted with their spren for some time before being able to inhale stormlight and glow. Including Dalinar, if you count the visions as spren interaction, which I do. So that also seems to rule out Lopen being a Radiant of his own accord- Rock would have noticed if he'd had a spren.

[Oudeis]

Rock would have noticed if he'd had a spren.

 

I'm not quite as confident as you that the visions indicate Dalinar has been "interacting" with his Spren for a while, but remember he also Invests after saying two Oaths in quick succession. His case is clearly atypical.

 

As for Rock noticing, recall that Rock didn't seem to notice Glys. I get that Rocks spends much more time with Lopen than Renarin, but he still spends enough time with Renarin that it's suspicious he never noticed Glys. We saw that Ym's spren was very, very secretive, that even Ym could rarely talk directly to her, so presumably Glys was just that secretive. It's possible Lopen's spren is the same way.

 

I happen to agree with you that Lopen is a Squire, but I'm not totally sure and I wouldn't tell anyone disagreeing with me that their position is implausible.

[Natans]

I always thinked that the WOp about squires in book 1 are related to the various fast healing wounds that bridge 4 man sustained. in the top of my mind I can think in the shoulder injure that Teft got and that "should" impair his fight ability but didn't, Skar "almost but not quite arrow in the knee" that healed very fast and without side affect, and dabid and hobber injuries in the begin of book.

Side note why this could be relevant? Well fast healing are evidence that almost preclude stormlight use, see Kal himlself and latter Dalinar in WOR that when fighting Szeth did't was bothered by his previous wound =)