We ramp launched and retrieved the J/24 (4 foot draft, fin keel) many times and have ramp launched and retrieved the Beneteau First 310 (4-3 draft) when required. Have done both with an extender (with wheels) and with tow straps. Takes a decent length ramp that you won't run off the end while you drop the boat deep enough to float it or drop the trailer deep enough to clear the floating boat on retrieval. Retrieval generally required getting in the water to some degree but can be avoided with proper planning regards tie down/guidance lines and keel line. Have to be careful that there is enough tongue weight when the trailer comes off the tow vehicle so that it doesn't tip backwards as you are preparing things and rolling it into the water. Others have also given some good guidance regarding tying the boat/keel to the trailer before you attempt to pull out and the need for a good operable front wheel on the trailer or wheels on the extender. The 310 weighs about 7,500 plus the trailer and when I pulled it, I had a buddy strap his diesel pickup to the front of my Suburban in order to pull it out, weight coming up the ramp was bit too much for the Suburban by itself. The launching is easy! ;-)
My J/24 trailer for many years did not have a ladder/bunk at the bow but I added one after 25 years! The 310 trailer does not have one either. Only issue with retrieving without one is that since you don't have anything to guide the forward position of the boat, you have to know where the boat sits on the trailer fore and aft so you can get it in the right spot before you pull out.
I would not have any concern with launching and retrieving with your trailer. But, the first time or two you retrieve, it will be an ordeal. After that, you'll be an old hand at it and you will wonder what all the fuss was about. And, plenty of helpers to run guide lines, etc. helps.