In A First Course in Modular Forms, Diamond and Shurman leave as an exercise ($9.3.3$) that every complex Galois representation is finite. While I think I have worked through this exercise here, this solutions seems sort of strange to me, because most other sources just state this fact as if it is obvious, giving no indication as to why it is true. However, this solution does not seem very obvious to me. (Of course, that could just be because I haven't spent enough time thinking about these things.)
Is there a better way to understand why complex Galois representations are finite? I've heard it informally explained that this happens because the topologies on $\mathbf{G}_{\bar{\mathbf{Q}}}$ and $GL_{d}(\mathbf{C})$ are incompatible, with too many open sets on the latter. While the proof I posted above does illustrate this, I'm wondering if there's another proof that may be more to my taste.
Bonus/Related Question: it has been my assumption all along that the topology on $GL_{d}(\mathbf{C})$ is the standard one. However, another comment D&S make leads me to wonder if I'm wrong. In discussing the relationship between Dirichlet characters and $1$-dimensional representations $\rho : \mathbf{G}_{\bar{\mathbf{Q}}} \to \mathbf{C}^*$, they say that to check continuity of $\rho$, it suffices to check that $\rho^{-1}(1)$ is open. This seems to imply that $C^{*}$ is given the discrete topology. Can anyone clear this up for me?
Thank you in advance!