Yes, this looks like it's what you had already, so it should continue to work if it already worked, if these are in the same script with my additions and edits. If I had added an ON JOIN handler, it would need to be combined with your existing one. When I want to make certain that an event happens to everyone, I use "*" instead of "1" for the level, to make sure that someone in level 0 is also affected.

However, these events are not specifying a channel name, so they would attempt to activate in all channels you are inside, so if you visit another channel and they make you an op, they may not appreciate you starting to kick and ban there. That was why my examples were listing the channel(s) where it would take effect.

See /help event prefixes
for the ! or @ prefix that can avoid having events trigger when you join or you change nick, or which do not trigger unless you have @op level

In fact, it should work better now, because your original BaneaUsuarios alias used /halt, which means that your loop for the nick change would have halted after checking the 1st channel and would not do anything in the other channels.

Yes it can be a problem if you need to a lot of kicking and banning. One way to help keep yourself from flooding out is to make sure that tools/options/irc/flood has the box checked 'enable flood protect'. I believe that also checking 'op commands' would apply to putting these kicks and bans into the que, so that they might be delayed to prevent you from sending too many too quickly. As for the other settings, you might need to adjust some of them to make your server happy, if you get flooded off anyways.

Something else that might work is a script that helps combine several mode commands together instead of sending individually, so instead of sending
mode #channel +b nick1_mask
mode #channel +b nick2_mask

... you could send
mode #channel +bb nick1_mask nick2_mask

... and this should count as 1 ban by the server flood controls. You can google for keywords mirc pushmode
and find it on hawkee. I haven't used it, so I can't vouch for it. I did help someone once using a script that called a pushmodex alias, so they apparently found reason to modify it, but if this works it should also help avoid flooding you off.

I say I can't vouch for a script I have not used, because there have been some cases of hawkee or other scripts not working or worse. For example, I had 2 times when someone came for help with a cricket game script that didn't work. It turned out the script was written so that you couldn't start a game without a specific variable already set, but the script wouldn't let you set the variable unless that same variable was already set. Another time there was a script that claimed to be a channel protection script, but it had socket code inside that put you into their hidden socket bot army.

Another place you can find scripts is at the .info site I mentioned here https://forums.mirc.com/ubbthreads.php/topics/270675/re-question-to-the-chat-logs#Post270675
and if there isn't a decent pushmode style of script there already, i'll ask around and see if one can be added