I suppose this is possible, but unlikely. We are largely ants to It; and out of sight is normally out of mind. It is an eternal being; a year is nothing to it. I expect it doesn't even notice the time between hunts. Something tasty wanders across one of its favorite places and it strikes. It can pull all the information it needs from the mind of the person it decides to torment and consume. I suppose if it had to work to find its meals, it might spend a minimal amount of time on it, but it doesn't.
I expect it could, yes. Without a doubt it could make Richie feel and experience those sensations. I suspect it could also make its mark more personal and lasting. The monster claims to have killed the librarian Ben loved as a child; she died of sickness/disease. But to some degree, I also think it was talking crap too. I think the creature is just impeded enough by our reality that it must work within certain constraints. To be physical it must take a form and all the weaknesses of that form. It is a package deal. To do things to people it must interact with them, often physically. The monster can do all sorts of things to people, but doesn't MOST of the time for two simple reasons:
1. It can't be bothered. We are ants and out of sight and mind unless it is eating or entertaining itself.
2. It cultivates its personal game preserve. No point in driving away the meals.
Can the monster give the Losers great wealth, long lives, etc.? Yes. Can it cause disease, blight, and other things that one would normally attribute to a malicious spiritual entity? Yes. Is there a cost for doing such things to the monster? I submit that it is quite costly. There are rules and constraints that the creature must abide (however angrily) to enter our reality. When it takes physical form, it takes on the weaknesses of said form. This is clearly a cost, not a choice. It can easily kill, whether by curse or agent (when it rides a dogsbody) but it doesn't do this often. Why? Cost. Everything the monster does indicates that it is lazy or thrifty. It can do amazing, terrible things. Why doesn't it do them all the time? It certainly isn't held back by any moral or ethical constraints. The only conclusion is that taking physical form comes at a cost of some kind. That is why it doesn't chase children too far, which allows some to get away. Why does it go back to the Clown shape (one of many favorites) when it isn't pulling a form from a victims's mind? Again, it has practiced this form and it requires less effort. Why isn't it riding dogsbodies all the time? Again, it comes back to effort and desire (it doesn't always notice us and cares less). While we may never understand the cost or be able to count it, there clearly is a method to this madness. I went off on a tangent here, but I think the answer to you question is yes I think It can do all that it threatened and far more, but I also think it was talking crap in that it had no intention of doing something so costly, when it had other methods of getting what it wanted (and soon) without near so much effort or expense.