Main thing here was adding enter mapping in vim to

insert newline without leaving normal mode

tmux/.tmux.conf

@@ -1,3 +1,8 @@
+#remove escape delay
+set -s escape-time 0
+
+set -g default-terminal "rxvt-unicode-256color"
+
 #change C-b to Ca
 unbind C-b
 set-option -g prefix C-a
@@ -31,7 +36,9 @@ set -g mode-keys vi
 if-shell '[ $(echo "$(tmux -V | cut -d" " -f2) >= 2.1" | bc) -eq 1 ]' \
     'set -g mouse on' \
     'set -g mode-mouse on; set -g mouse-resize-pane on; set -g mouse-select-pane on; set -g mouse-select-window on' 
-#    'set -g mouse on; set -g mouse-utf8 on' \
+
+set -g mouse on
+#'set -g mouse on; set -g mouse-utf8 on' \
 
 bind-key Tab last-window
 bind-key BTab previous-window