I don't think the scry makes up for the card disadvantage here. As for offering, I think it's meta dependent. I'm constantly seeing enchants, and artifacts. 4 life is a big deal here. Even if it's late game to destroy an arrest I placed (terrible play, I know). Obelisk is a possible replacement to any of the finishers, but I don't think it's as good.
Edit: I didn't answer some of your thoughts as well as I could. The deck has answers for just about everything. When I tested it online, the only game I lost (out of 4) lasted ~30 turns, and I never drew any of my bombs (and not much card draw either). I'd have won if any of my bombs had come up. Also, when I finally drew a draw card, after those 30 turns, I stupidly targeted the opponent, so I'm not even sure I'd have lost (I really hate that system, btw).
edit2: Arrest is also nice, btw, because it has synergy (albeit minor) with
Soul of Ravnica as it will count as a white permanent to give you that 1 extra card draw. fwiw
edit3: so I guess the better question here, is how do improve the removal/control package on this deck? I accept that Solemn Offering could possibly go, but I do like the small life gain, and I believe it's valid against a lot of/most (non-pure agro) decks. I'd be interested in any suggestions that stay within my two colors, are not inherent card disadvantage, and ideally are cheaper. I just wish we had some cantrips that were relevant, but I guess we don't - le sigh.
Question: should I consider courier's capsule over think twice - or inspiration? it doesn't exile, and it has lower mana requirements per turn, but it's also not instant, so it's a bit later game. thoughts?