Am I allowed to create a google site to help manage my platoon?

Just don't do anything like that on a system that isn't DOD or DA controlled. That's what AKO is for.

A battalion commander of mine told us company commanders to use WhatsApp. I dragged by feet as long as I could before he pointed out I was the only one not using it. Not long afterward top brass pushed out it couldn't be used and now we are on MS Teams.

Years ago, a team leader over me made us put all our personnel documents on the cloud. They were secure and all that, but he had control of all the sub folders for each individual soldier of his. Fast forward, he got caught up in a EO complaint, and then he locked out the complaining soldier from her own personnel folder.

What I ended up doing to help the female soldier (since I was a Jr NCO in the section, and had admin access) was download all her documents and then e-mailed them to her directly. The EO complaint wasn't against him (he was helping an officer friend of his), but it pointed out a weakness that could be abused. If she went after him too for this he'd be done.

COL's are getting in trouble in the last few years regarding un-secure Apps on personal and gov computers for official business.

You're just better off using government owned or sponsored means for work and technology. Lets say the system sucks, and all data is compromised and lost, well at least you wont be holding the bag.

Don't try to use something else and don't try to re-invent the wheel. There are already DOD accredited resources you can use in AKO. Use them. Save yourself the headache.

Google is a great tool but you have to ensure you are only using it for personal products. I love Google personally. I have my "I LOVE ME" book on my Gdrive. It has come in handy when I need to send a copy of some random document on the spot. When it come to collaboration it can help but you should be cautious of being anything that is FOUO on Google. My Gov computers won't let you access Gdrive. But I would keep trying to see how you can improve your products with new and emerging tech. I used Google to send out questionnaires for our FRG meetings when our BDE was deployed. It was great. We were able to get questions from family members without them being identified.

I would not recommend it. You can use Office products and save that information using local resources instead of putting information out there on commercial platforms. Depending on your network security it might flag the sites right out of the gate.

That is a really interesting question!! I do not see a regulation that prohibits alternatives. I would thing that it would more have to do with cybersecurity than anything else. As with many cloud services there are vulnerabilities. Forbes recently had an artical about cloud users bypassing corparate security using Google cloud.

If you're looking for something like MS Teams, you are in luck.
We have been on MS Teams since April.

Nope. Like CPT (Join to see) just mentioned, that’s what AKO is for, use it. It’s encrypted, DoD accredited, and will not get you in trouble.

I'm going to leave it to some IT experts to give you the book answer, but will point out a problem I experienced.
One of my staff tours in the early 80s involved the planning for a $130B program that had a planned life until 2030. HQMC would not provide PCs we could do our work on, so a friend who had a TRS80 brought it in and I brought my PC Jr in. We put the planning and operational plans on the two machines. When we completed the two years worth of staff work, we handed it all into HQMC in hard copy since they didn't have the capability of converting the programs we were using. We always heard it took six months for several clerks with TS clearances to put the documents into DOD language.