Ok, now I can reply. There are many aspects one can choose to focus on in this chapter, so it can be interpreted in several ways, I want to single out a brief passage, prior to you quote of "We cannot in any property of speech...", he speaks about how time implies succession, and then says that:
"This fiction of the imagination almost universally takes place; and ’tis by means of it, that a single object, plac’d before us, and survey’d for any time without our discovering in it any interruption or variation, is able to give us a notion of identity." (pp.200-201)
I think it is important to point out, that in Hume's use of the term, "fiction", does not mean what we mean by it today, something not being "real", or belonging to mythical tale or a novel. It simply means "more than is warranted by the empirically available evidence." It is real, in the sense that we do experience the identity of objects, but when we look at the evidence, it turns out to be weaker than we would like.
He says, on p.203:
"When we fix our thought on any object, and suppose it to continue the same for some time; 'tis evident
we suppose the change to lie only in the time, and never exert ourselves to produce any new image or idea of the object. "
That speaks of your concerns that each perception is different, and it is by resemblance that we posit continuity. True. Now he says, on p. 204:
"
I survey the furniture of my chamber; I shut my eyes, and afterwards open them; and find the new perceptions to resemble perfectly those, which formerly struck my senses. This resemblance is observ’d in a thousand instances, and naturally connects together our ideas of these interrupted perceptions
by the strongest relation and conveys the mind with an easy transition from one to another. "
Italics mine. Each perception is new, and he does not want to distinguish between objects and perceptions. Yet he still speaks of "my chamber", if he didn't have a notion of identity, he couldn't speak like this, because he would have no way to separate his chamber from anything else.
An important, passage, I think, is this:
"We may begin with observing, that
the difficulty in the present case is not concerning the matter of fact, or whether the mind forms such a conclusion concerning the continu'd existence of its perceptions,
but only concerning the manner in which the conclusion is forrn'd, and principies from which it is deriv'd."(p.206)
Italics and bold mine. So, I don't think there is a tension is speaking about identity as we do, in regard to the The Ship of Theseus, only that Hume goes deeper and presents us with problems that go beyond, or are deeper in a sense, than the example of the ship.
As I said, one can pick out many quotes here, supporting different views, so one should keep this in mind. What I quoted here is what I think makes sense from a holistic perspective, but this can be debated.