Star System warp is something that they never seem that consistent on. In BOBW they slow down, in TMP they say they have to risk going to warp to get to V'Ger quicker, and in the episode where Bashir is revealed as a Changeling, Dax seems distraught that Kira suggests going to warp as they could fly into the star.
Whilst in TVH they go to warp not only in the Sol System for the slingshot, but with the planets atmosphere. Then in ENT we see the NX-01 warp out after barely clearing spacedock.
I would think that after the subspace damage warp causes was discovered, a ban would be placed on all warp travel in systems (especially inhabited ones), so as to not damage local ecosystems, etc.