Good Idea. Let it roll!
100 / 105 series are very reliable vehicles.
I believe their turning circle, with Low Range engaged and with Diff Locks engaged is shorter than other vehicles in this size, even better than Prado, if I recall correctly. Very nimble. The only limitation is the size and angle of the bonnet, which limits its view, especially when climbing uphill. May need a camera to see the blind spots when in serious off-roading. ARB bumpers and Suspension Lift is good.
Overall, very good off-roader, even without any modification at all.