I would fully expect an Imperial ship to ram another if it was ordered. Remember, TNO is a miliary government employing 100% loyal clones in most lowlevel positions. If an Imperial craft were crippled and it's Captain ordered it to ram another ship, it would.
And of course, the Executor and Eclipse were capable of ramming small vessels and taking minimal damage.
No, not abolishers! Ramming ships, ok, I've used that tactic many times in the past before it got banned. Abolishers...well lets just not go there and never make them allowed again. (Not to mention the fact that Robot Ram Ships are canon, whil abolishers aren't)