Mac networking safety?

[Riku7]

I was trying to search for answers and browse the sharing settings but the network and server jargon doesn't make any sense to me. I guess I'll just have to ask from you guys.

The situation:

So I have two macs that I wish to use simultaneously with the same mouse+keyboard. I found a way to share the sound and I've done screen sharing before. But now I live in a place where I'm not the only user of this wifi, so I'm not feeling so good about doing screen sharing wirelessly.

I managed to establish a closed connection between the two by "Create network", but it's a shame that it cancels out the access to internet. My iPad has 4G and iPhone has 3G, but apparently the operators don't allow tethering.

These computers have been connected before, and they can see one another in the network when in the same wifi. To my horror, I realized that I can access the files without any passwords so either the files were unprotected or I had granted some password protected access before and it's still using it. For now I shut down all sharing from both computers but I'm still not feeling completely safe because I have no idea what others can or can't see.

I'm a complete dummy with the network jargon abbreviations. If there's no other way but to fiddle with those settings, some newbie-friendly reference would be highly appreciated.


The problem summarized:

How should I share files and screen between my two computers securely without losing the access to internet from at least one of them?
If I buy an ethernet cable to connect the computers physically, does it cancel out internet access like private wireless network does?
Is there any way how I could reliably monitor what other computers can see and access when my computers are in the same wifi network?

 

[simsaladimbamba]

Teleport can help use one mouse and one keyboard with two or more Macs.

As to the network, if you are connected to the same wireless network as others, use the SHARING preferences in System Preferences to allow and deny access to the users you want.

I have two Macs on the same network and the only way to access data from one via the other would me having to enter the account name and password.
As I am pretty sure, that neither of my computers get stolen to access my network, I can live with Keychain Access storing that data, since it would require an admin password to read out passwords.

Doing so, using the wireless LAN to share files, will also allow you to use the internet.
If no one else has your account credentials, all they will see is your computer, but they will not have access to your data, unless you give your account credentials away or have no password set for it.

 

[Riku7]

Teleport can help use one mouse and one keyboard with two or more Macs.

As to the network, if you are connected to the same wireless network as others, use the SHARING preferences in System Preferences to allow and deny access to the users you want.

I have two Macs on the same network and the only way to access data from one via the other would me having to enter the account name and password.
As I am pretty sure, that neither of my computers get stolen to access my network, I can live with Keychain Access storing that data, since it would require an admin password to read out passwords.

Doing so, using the wireless LAN to share files, will also allow you to use the internet.
If no one else has your account credentials, all they will see is your computer, but they will not have access to your data, unless you give your account credentials away or have no password set for it.

Teleport seems good, I've installed it onto both computers but I'm not done setting it up quite yet... So it seems that it'd require enabling of those wifi sharing options anyway, the ones I was trying to avoid. If wireless sharing wasn't so scary, I would already be using the usual screen sharing feature without the need for extra gimmicks.
When I had sharing turned on before, the computers could see each other. The scary thing about that was the fact that it did *not* ask for passwords.
I might learn to trust the privacy of this shared network if there was a way to make these two computers forget one other again. IF this smooth accessibility is because of some active "always allow" settings. If wireless is the only way, I'd first like to reset all access somehow, then turn sharing on again, see what it really looks like for a stranger, and test if it really asks for a password. That would bring me the peace of mind.
As for Teleport, I didn't find any guides on it that even mentions the System Pref sharing settings, even though it seems to be the crucial thing to enable first. To use Teleport, which types of sharing are absolutely necessary for it to work? Because there's a list for enabling different things individually.