Magister

yes it is possible to run in a linux distro, as a jar is generally just as usable in linux as in any other os as it is simply dependant upon java. ubuntu server is fairly easy to set up once you get going, and headless is done fairly simply over ssh now as far as running it without a gui, you have a few choices, you can utilize screen to maintain the sessions and just add the nogui to the script that starts it option two, look into mark2 as it works well on ubuntu and can make managing the server much more easy depending on your level of knowledge with ubuntu

hamachi is a VPN which doesnt generally require port forwarding if you have a router that has vpn passthru, it has been a long while since i used hamachi and instead just switched to other methods of vpn, but if you already have port forwarding setup in your router to the pc with the server being hosted on it is best to just get rid of hamchi as it adds unneeded things that can be the root of the issue. as far as the ram goes if it is just the two of you, you can try lowering the ram for the sever to 1GB and increase it as needed if you get out of memory errors, same for your client. since it is a small server you can start out low and increase. for low player count server you tend to need more cpu power than ram anyways. you may also try closing out any unneeded background applications before starting the server and client.

hamachi could be the issue, as far as getting the request time always when one of you tries to ping the other but works just fine the other way around, that sounds like a firewall or ping block in a router. now just because you are using hamachi doesnt mean you dont need to forward ports with some routers or networks, check the hamachi settings sand make sure neither of you are using fallback connections within hamachi, if all else fails then try doing a direct connect if able and rule out any issue you may have with hamachi

technically it is not an infinite loop since the number of times the minimum stone can be used is finite, also even with the removale of the infinite wood a tree farm can produce more wood at a faster pace as viktor pointed out above

this has actually been around for a long time when using TE and EE3, it is even more exploitable with TC3 as it becomes easily self powered

try disabling the windows firewall and having them try a connection, also any other firewall you may have installed, then if you have multiple firewalls bring them back up one at a time till one stops the connection. if with the firewall down they are still unable to connect then double check your port forwarding in your router and make sure your pc is set to have a static ip. also if you have multiple network adapters you may want to check your priority settings for them.

your internet could be part of the problem if they use any kind of traffic shapping, as far as your problem your friends are having it sounds like a lag or sync issue, first thing to do is look into if the hamachi connections between you and them are functioning properly or if they are using the fallback ports for communicaiton.

if you are meaning to put the IP address in that the server should bind to in case you have more than one adapter or virtual adapter, that is in the server.properties files in the server folder.

remotly scanning ports can be viewed as an attack depending upon your router or internet provider which can cause false readings, but it can be used just do so with caution and it is always better to start at one end and work out, then start at the other end and work in till you find the issue.

you need to test your upload speed on your server, also try reducing the view distance in the server properties, you are getting an overflow error and only a few things cause that, all of which are basicly more data being sent than the client is able to handle what the server is built upon should not matter and generally it is related to mod or something in the world causing it. seeing how much data is being sent can be done with the netstat command in a terminal, this command does vary in function based on your OS and you may need to look up the various switches or arguments for it based on your OS

try pinging the localhost on the mac, then the router then another computer, then do the same thing with another computer that you are trying to connect to the mac from. when the ping fails what does it say? also you may need to turn off any firewall the mac may be running if you open a console screen on the mac and use the nmap command on local host it will tell you what ports are open

disconnect.overflow is showing when a player is trying to connect, that can be caused by a few reasons but generally i have seen it when alot of information is sent either by a mod or by what is in the area the player is logging into, you also have memory leaks which by itself isnt that bad of an issue but can compound issues, what i would suggest is that since the server is custom made you need to rebuild the jar from scratch and check each mod a few at a time till you find the one causing the problem, you may also want to see how much network information is being sent or recieved when a player connects.

if you can post a full server log that might help figure out what is going on, have you tried to redownload and use a fresh server?

java -Xms1G -Xmx1G -jar minecraft_server.jar nogui you dont need the - between the .jar and nogui

first off readyboost does not work that way, secondly what version of java are you currently using? have you tried updating?