You should have no problem pulling your attachments. The PT comes with a small pin/bail tab lock. I changed it out to a regular 1/2" hitch pin w/ handle on top and clip on bottom. I use it regularly to tow my spreader and a dump wagon, and I've also towed a rented aerator w/o problems.
With your spreader you may have to rig something up to turn it on/off from the operator's seat. The OEM cable on mine was not long enough. The rear engine of the PT adds a lot of length between the operator's seat and any rear implement. I contacted the spreader mfr, who put me in contact with their control cable supplier who actually made up a longer cable assembly for me. I got one a couple of feet longer than the actual straight line measurement since I have it positioned on one side of the tractor, not down the midline. When you make turns in one direction, the articulation demands greater cable length. Hope that helps.