Fractional First Officer reported there are no lead-off markings for the end of Runway 18; the taxiway between Runway 36 and 4L is narrow; and the verbiage and poor runway and taxi lane markings make the hot spot area unclear at LIT.

Narrative

When taxiing to Runway 4L from the FBO; we were directed to back-taxi down Runway 36 because of construction on Taxiway Alpha. After crossing the displaced threshold for Runway 36 we turned left to proceed to runway for 4L. There are not any lead-off markings for the end of Runway 18 for either direction. Plus; the transitional tax away between 36 and 4L is narrow. This creates unclear markings for pilots to follow when taking this path and could result in a wrong turn.Suggestions: Apply lead-off lines from Runway 18 to Taxiway Alpha and the bridge taxiway that goes to Runway 4L. Widen the taxiway between the departure end of Runway 36 and the departure end of Runway 4L to allow for sufficient space for aircraft to transition from one runway to the other when back-taxiing to depart on the opposite runway. Expand the verbiage in the hot spot description to identify that the transition taxiway between the departure end of Runway 36 and the departure end of 4L is not marked or labeled. Repaint all runway markings [and] taxi lane markings in the hot spot area.