You phrase your latter of your two questions as 'Can the word mean something broad like “universe” or “creation”?' I presume that you mean Can the word 'earth' in v. 1 be meant by the author as half of a merism the total of which is meant as 'the whole cosmos? I shall offer my answer to that in a moment.
It seems to me your first question is whether the Hebrew itself can support the idea that 'earth' in verse 2 is meant in a third way, different from that either in verse 1 or that in verse 9-10. Given what I answer below to your latter question, I see no reason to think that that in verse 2 must be different from that in v. 1.
Now, in regard to whether v. 1 involves a merism. I do not believe that that question can adequately be answered by an appeal narrowly to a knowledge/opinion of the Hebrew. This is because, short of some science-fictional ideas to the contrary, the nature of our efforts to explain the origin of the natural cosmos is an effort that presupposes that the proper audience of our efforts thereto is a ground-based human audience (ourselves, and our fellow terrestrial humans both present and future).
It obviously is a fact that there exist among humans different stories and ideas as to the origins of the natural cosmos. These cosmologies, of course, include both theistic and non-theistic stories, both ancient and modern. Their multiple existence commands of us an explanation for it.
The basic explanation for the existence of multiple cosmologies among us is an explanation having at least two of exactly three parts:
(a) The single primary part, that we have a natural drive to know, and to understand, how and why the natural realm came to be.
The two second parts are:
(b) we do not always agree with whatever such story that we have inherited; and
(c) human expansion from any local land often has included one or both of: (i) mis-remembering some of the details of the inherited cosmology; (ii) forgetting of the inherited cosmology, allowing the outlying population to innovate in terms of (a).
The cause for (b) may be a complex matter, such as that including socio-psychological and political issues. But the fact of (b) seems to be the main reason why there are multiple cosmologies among humans.
But, it is extremely important to note that, given our natural drive to know and understand how and why the natural realm came to be, neither or both (b) or (c) tells us either:
(X) whether humans themselves initially had one cosmology or multiple cosmologies, and
(Y) Whence the initial cosmology or cosmologies.
For (X), it is conceivable that humans originated either: (mc) in multiple independent social cultural locations (societies) and, thus, possibly with multiple independent different cosmologies; or (sc) in a single society and, thus, possibly with a single cosmology.
Now, the barest Biblical conception of the origin of cosmology is this latter (sc): humans originated in a single society, and thus most naturally began with a single cosmology.
But, regardless of the origin of cosmology, per se, there seems to be one most basic universal distinction which is presupposed in our drive to have an origin of the cosmos: the Terrestrial Default Binary. This binary is formed by the fact that we normally are bound to the life-supportive and life-filled half of our cosmos.
Obviously, then, our normal ground-bound frame of reference in this binary could be your 'earth' in Genesis 1:1. This would explain the claim, by many, that the Hebrew phrase 'heaven and Earth', typically is meant as a merism: an all-inclusive term for the entire natural cosmos: the Great Wide Far Up There and the Great Wide Down Here. Heaven and Earth.
And I notice that 'erets' in vs. 9-10 does not include the h' prefix of that in v.1.
Heaven and Earth = h'shamayim ve'et h'erets.
Finally, we cannot accurately assume that Genesis 1 is an account purely of God's creation acts. Instead, it seems to be more a report as to what God did. The distinction here may be subtle, and then some, until we see what the account says that God did.
First, the account reports that God not only observes things, but names things. And the basic route to naming a given thing is to observationally distinguish it from its counterpart. Verse 1 does this implicitly. But verse 1 does so for the whole cosmos: h'shamayim ve'et h'erets
According to the above-mentioned Terrestrial Default theory, the first observational distinction which the account reports regarding Earth herself is that within which she abides from her immediate wider cosmic context: the directional light of the Sun. The moonlight does not rule the day, nor is the moonlit night thereby called 'Day'.
That is, according to this Terrestrial Default theory, v. 4 is not describing any action, on God's part, upon the light and dark. Rather, it is describing merely an observation, on His part, of the fact that h'eretz abides the distinction (from an 'unmoving' space-based point of view, Earth rotates). Therefore does God name the distinction, and this specifically in terms of Earth: Day and Night.
So, according to this theory, the first five verses are a progression, and a particular one. The account, which includes Genesis 2, begins with an initial prime distinction, and the direction of that prime distinction is that followed by the rest of the account: General-to-special. Heaven and Earth....Man and Woman.
Second, given what the account says, the account is conspicuous for what it does not say: It reports that God names things, but only five things. The account has many more than five things! (vv. 5, 8, 10)
The narrative fact is that God made humans in God's image and likeness. The empirical natural fact is that humans have the capacity to develop a language from scratch, and this most effectively and quickly from a combination of human bio-cognition enviromental cognition and socio-interactive cognition.
If we unpack the implications of all this, the Terrestrial Default theory of Genesis 1 concludes, only to begin with, that there is a particular initial conversation that God had with Adam:
- God: 'Yam.'
- Adam: 'Mayim.'
- God: 'Shamayim.'
- Adam: 'H'shamayim.'
- God: 'Erets.'
- Adam: H'erets.'
- God: 'Day and Night.'
That's seven exchanges, the final one containing not only one, but two names. This is in keeping not only with the total seven recursions which the Terrestrial Default theory finds in the binary account (Genesis 1-and-2), but with the final, seventh stage of that recursion: Adam finally finds his humanity, as well, instantiated in binary. And that final stage in the exchange naturally is the first two things that God names. That is, in five names together does God identify to Adam the non-living half of Earth's life-support system.
This is how I reason both (1) that 'earth' in vs. 1-2 is not the same as that in vs. 9-10; and (2) that 'earth' in vs. 1-2 is, within the proper frame of reference of both humans and God, our own ground-bound half of a merism (heaven and earth) that the account's author means for 'The Entire Created Cosmos That Humans Naturally Observe'.