Several characters predicted that the Crescian reaction would be harsh.
Much of the law-abiding population of the town had already left, but he population still in the town had been ignoring the Palace's orders to evacuate the town and move elsewhere. They had disbanded their own town council and allowed the Frummagems to run the town instead of any legitimate authority. The cops really were all corrupt. Many of the remaining townspeople really had no respect for Crescian authority. Knock and Anadyne had no trouble getting the townspeople to attack Toma, for example. Toma on the next page: "Your cops - and I'm presuming your entire godforsaken town - have gone right off a cliff" and "If kidnapping and smuggling are the only work you could find to save yourselves then you're not worth saving!" And that's Toma, who's incredibly nice for a Crescian officer! Bell, of course, we make the townspeople seem even worse than they actually were. They won't have any credibility if any survivors complain about what happened.
He was presumably keeping Bell up to date. A lot of good that would do! We saw that Toma was reporting to Bell, not directly to the Palace.
No one would have thought that Ethelmik was a target, and it wasn't. It was common knowledge that Ethelmik would be evacuated and destroyed within a year anyway, so there would have been no point in Alderode or anyone else attacking it.
That decision to do that had be made years ago! The town was costing too much, so it had to go.
Hetr and his army had just left the previous day. It wouldn't have taken him more than a day to return.
The constructs had probably been stored in the old mines under Ethelmik and left when Hetr did, so it would have taken only one day for them to return, too. Even if not, they were probably passing through the area on the way to the front. In any case, we know that Bell hadn't intended to destroy the town until Elka told him that the silver had exploded there, which was just a day earlier.
We know what much of Bell's plan is because Bastion explained it to Rahm. It obviously will take months or years for that part to be completed, so no.