As always try to make a new user. But neither should cause too much of a problem. The only thing you need to careful of is theming.
What is kind of cool - but could be a problem - is that sway can respond to i3msg. You can also issue commands with i3-msg or even with i3. Which could make them conflict. To overcome this you can manually set the socket. If the the problem occurs leave it alone if it doesn’t
BASICALLY MAKE SURE YOU KILL I3 BEFORE RUNNING SWAY. DON’T BOTH OVER TWO TTY’S
If it occurs
Sway socket not detected
Using a swaymsg argument, such as swaymsg -t get_outputs, will sometimes return the message:
sway socket not detected. ERROR: Unable to connect to
when run inside a terminal multiplexer (such as gnu screen or tmux). This means swaymsg could not connect to the socket provided in your SWAYSOCK.
To view what the current value of SWAYSOCK is, type:
$ env | fgrep SWAYSOCK SWAYSOCK=/run/user/1000/sway-ipc.1000.4981.sock
To work around this problem, you may try attaching to a socket based on the running sway process:
$ export SWAYSOCK=/run/user/$(id -u)/sway-ipc.$(id -u).$(pgrep -x sway).sock
To avoid this error, run the command outside of a multiplexer.
Unable to retrieve socket path
Requesting messages from swaymsg -t on a tty may return the following message:
Unable to retrieve socket path
SWAYSOCK environment variable is set after launching Sway, therefore a workaround to this error is to request swaymsg -t [message] in a terminal inside Sway.