Israel does not have Palestinian hostages as you put it. See example from the BBC where there is a CLEAR distinction between hostages and prisoners.
There is good reason for this - it's defined very specifically in International Humanitarian Law. The following texts come from the ICRC:
"The International Convention against the Taking of Hostages defines the offence as the seizure or detention of a person (the hostage), combined with threatening to kill, to injure or to continue to detain the hostage, in order to compel a third party to do or to abstain from doing any act as an explicit or implicit condition for the release of the hostage."
And:
"It is the specific intent that characterizes hostage-taking and distinguishes it from the deprivation of someone’s liberty as an administrative or judicial measure."
And:
"Although the prohibition of hostage-taking is specified in the Fourth Geneva Convention and is typically associated with the holding of civilians as hostages, there is no indication that the offence is limited to taking civilians hostage."
And:
"Common Article 3 of the Geneva Conventions, the Statute of the International Criminal Court and the International Convention against the Taking of Hostages do not limit the offence to the taking of civilians, but apply it to the taking of any person. Indeed, in the Elements of Crimes for the International Criminal Court, the definition applies to the taking of any person protected by the Geneva Conventions."
Now we've established the distinguishing difference between the taking of hostages and prisoners as well as the reality that it's also prohibited to take soldiers as hostages, we can look at the claims levelled against the Palestinian prisoners.
What are the crimes they stand/stood accused of?
55% of the Palestinian prisoners released by Israel in the first three days of the first prisoner releases were accused of various crimes ranging from attempted murder, inflicting serious bodily harm, shooting at people, assault and placing a bomb or throwing an incendiary device.
21% of the released Palestinian prisoners were members of terrorist groups such as Hamas, Palestinian Islamic Jihad and Lion's Den.
What are the crimes the Israeli hostages have been accused of?
Precisely zero.
Hamas took Israelis hostage for one reason and one reason only:
"The International Convention against the Taking of Hostages defines the offence as the seizure or detention of a person (the hostage), combined with threatening to kill, to injure or to continue to detain the hostage, in order to compel a third party to do or to abstain from doing any act as an explicit or implicit condition for the release of the hostage."
If you don't want anyone to view you as a sneaking regarder for terrorism, take my advice and simply refrain from trying to create false equivalences, poisoning the well and so on.
Israeli hostage taking is NOT the same thing as Palestinian prisoners being deprived of liberty under International Humanitarian Law.
That's why news organisations such as the BBC does NOT equate hostages with prisoners.