The very small tank is likely the dryer, it has descant in it to trap any moisture that may be in the system.
First, Why remove the system? Engine driven sustems are easy to use, and generally reliable. If you are going without refrigeration
you can leave it and use the ice box for stowage... BUT if you are going to add an ac system later, you can do that with the engine driven system in place.
You may find it is not too hard to fix later.. but once you have scrapped it you will have much more trouble putting it back in.
Second, Chuck is right.. it is illegal to cut the lines and remove it yourself unless you have paid someone who has the recovery equipment
to pump it down... BUT if you are going to pay them, you might have them check it first to see if it can be fixed.
Third, If it were me... I would either fix it or just remove it myself....
if you happen to 'accidentally' open the system yourself, make sure to have lots of airflow and evacuate the boat
until you are well sure the coolant
has cleared... it may displace oxygen. If you 'accidentally' vented it, you would be able to remove everything yourself without trouble.