#3
Looking at the aspect of blue senzu, i agree that they are a useless wish from Shenron. Removing them would be a good idea.
Adding a new wish is a good idea but a wish that is 5 soul/s and 150 max souls isn't needed, there are already a lot of items that provide soul regeneration and plenty of NPC quests to increase our max soul.

Instead a new wish could be as follows:
+3-5% Dmg Against Monsters, or
+3-5% Critical Chance, or
+1% Absorb Dmg, or
2k Combat Points