^^
1. If there's no compression or encryption to look for, then jump straight to compressing your archive. Tools like XTool (
[1],
[2]) can act as precompressors for certain algorithms so you don't have to manually decompress the data when you find a compressed game. XTool handles it whilst making your archive.
2. Try
this. All the info you need is there and it is equipped with the required libraries to unpack FreeArc archives.
3. Never used it, batch files are just easier and don't trigger AntiVirus.
4. Making patches is a bit outside the scope of our forum since this is for compressing game backups. However, there are two AIO utilities I recommend to make patches -
Anadius' tool and ISXPM. Anadius' tool is easier to use but offers only XDelta whereas ISXPM offers more customisation and choice of patch engine (XDelta, HDiffZ or JDiff).