I used the 65k gold continuously until I had a little over 800 million git without issues at all, so I'm pretty sure you're safe to keep it on as much as you want. As for the x25 items, you won't get banned as it doesn't effect anything that is monitored (such as the rewards from Another Dungeons) since those items are delivered through server code instead of system code, but as mentioned in my post, if you pick up the wrong key item with it on it may have consequences, some more severe than others. Beyond the ones that outright prevent progression (as I listed in my post), I know that having it on when receiving prizes for finding "Hide'n'Seek Toto's" in Toto Dreamland will cause you to be unable to accept more than one prize. This does nothing but deny you some weapons, but my point is that there are things I have not listed that the x25 items mod can have consequences on. If I notice any of these, I will add them to the list of the post though. Outside the Toto Dreamland one mentioned above, I haven't had any other issues other than having an annoying amount of Key Items, Badges, and similar in my inventory.
So, short answer, you don't need to worry about bans, just be careful you don't mess up your game too much!
Just in case I misunderstood what you said, if you were asking if it is safe to have both x25 items and 65k gold on together, the answer is yes, it's perfectly safe. 65k Gold only affects Git gained from Combat, while x25 items does not affect anything gained from Combat, so their effects do not overlap in anyway.