In relation to this question: What screenshot tools are available?
Is it advisable to deinstall or deactivate gnome-screenshot when installing and using shutter? Or doesn't it make any difference (e.g. is there two daemons running now?)?
Activating shutter works perfectly, I'm just wondering whether the system gets bloated when installing a second tool to override the first one.
These tools aren't actually daemons running - but rather only run when executed or launched. It would be similar to having both OpenOffice and gEdit installed on a computer. Though they both serve the same function they won't collide with eachother.
You should be fine and safe to have both tools installed side-by-side
No not at all (unless your system has very little memory). Like Marco said in his answer these are two different programs.
It's just like having Firefox and Google Chrome running at the same time. However if you don't think your ever going to use one of the programs again, I would uninstall it. No point in wasting space.