1.IMO there's no reason to use the morning star turned off, I think if the player equips it he want to be on, cause it is a weapon. Any player wielding one WANTS the x1,5 damage multiplier and the x2,5 multiplier to wet enemys. It's A waste to use it turned off since it decreases durability way faster. so I think its better to aways be on when equiped.
2.For the grounded feature however I think the on/off function is usefull, yet situational. But, there's a issue... whenever the player drops it, it's turns on instantly just like a lantern. That's not good, cause we're talking about a weapon, not a light source. This is a issue cause I already left mine on, during daylight (i thought it was off), and when I came back it was out of fuel. IMO it must be off when grounded until the player turns it on.
NoteA: When off (both equipped and grounded), the Morning Star appears to be emitting light, but it's only a visual bug. It can confuse the player if its on or not.
NoteB: When grounded and on, the player is unable to auto pick the weapon and must be turned off to pick, this can take some few, precious instants when fighting hounds for exemple. Morning Star must be pickable at any given moment.
3.Electrical doodads (transistors) shouldn't be used as fuel, they are quite expensive and aren't batteries. The fuel should be nitre, which is fuel for various kinds of machines such as Ice Fligomatic, Endothermic fire pits and Winona's Generator. Nitre is also needed to craft the Morning Star! You should keep the +18% tho. I think Volt Goat Horns could also be used to refill the weapon around 40%.
4. I like the idea of Charging Morning Star with a lightning strike. I gives more power the weapon over Warly's Electric Jelly. However, I think some changes are needed. First, there's 25% chance for it to disappear, that's fair. The problem is... it... disappears! It just vanish from existence! I guess it's fair to being destroyed and dropping some of the materials on the ground. I think it should drop one transistor/doodad (two doodads are needed to craft) one Volt goat horn and no nitre (it was consumed, so they won't drop). Second, the weapon should be refueled back to 100% when stroke by lightning. Third, it should be charged for one and a half day and stack up to 5 days if hit more than once. Fourth, it should be also chargeable while in inventory if the player get hit, but only charge for one day (since the player himself absorbed part of the lightning and took damage from it). Also i think if charged while in inventory, it should reduce the destroying chance to 15%.
Note A: Remove the destroying chance if the first lightning was successfully absorbed. This will allow Wickerbottom to use "The end is nigh" book to charge many Morning stars at once and not destroying them all.
Note B: If the player is wearing Eyebrella, Rain Coat, Rain Hat or any item that protects from electric damage the Morning Star shall not be charged.