1.Does MyEclipse 5.5GA only be install on Eclipse 3.2.2?
Yes. 5.5 GA is fully compatible only with Eclipse 3.2.2
2.Should I remove MyEclipse 5.1GA before install MyEclipse 5.5GA or I can update via “Find and install”
Since the 5.5 GA release provides support for a completely new Eclipse SDK platform (3.2.2) there is no upgrade path from MyEclipse 5.1.x or earlier versions due to platform API changes. A full installation must be performed for this release.
3.Are there any problem if I want to install Eclipse 3.2.2 + MyEclipse 5.5GA and not to remove eclipse 3.2.0 + MyEclipse 5.1GA.
There wont be any problems if you have multiple versions installed
https://www.genuitec.com/forums/topic/installation-can-i-have-multiple-versions-installed/