Pilot reported the closure of SFB Tower led to multiple traffic conflicts. Reporter suggested the Tower be open 24 hours a day for optimal operational safety.

Narrative

ATC Tower closed. At approximately XA:08 we announced on CTAF we were going to cross 09C. Aircraft Y was on base for Runway 09L. Immediately after making our CTAF call the Aircraft Y GA aircraft announced they were switching to landing 09C because Aircraft Z was on the runway." There was no Aircraft Z on 09L but they were perhaps seeing another Aircraft Z taxiing on Bravo. We had to come to a complete stop before crossing 09C because the aircraft last minute announced they were going to land on our runway. We had them in sight. As soon as we stopped; Aircraft Y announced a change of plan yet again that they were switching to 09R. Before all this we observed Aircraft A departing 27C while Aircraft B was landing 09L. They came in close proximity.For safety; Sanford needs 24-hour ATC. Please advocate for this as much as you can. A company page declared preferred runway would assist pilots being on the same page. Coordination with local flight schools would be helpful especially if we can all get on the same page of preferred runway during non-Tower operation. I believe it would be best if 09C/27C was not used at all during non-Tower operation. I believe a safer setup for SFB during non-Tower operation is for the GA to use 09R/27L and stay south.Frequency: We are dealing with this every day. Severity: This is a safety issue. Aspects of this are an area ofcontrol for us. See above."