Maintain there lo. You need more blake dagger for other Agi/Str hero 1st. Jugo is quite strong already at P4. Mine still staying at P4. With full enchant now jugo already got 6.8k attack. If he goes orange and improve to 7K but lose 50 leech is quite bad.

Slowly upgrade. When i was at your level, i only secure 2 mine. Other mine mostly will get hit (coz level 35 only lol). Think it as an extra.
No. Mostly top player will try to get rid of him. He does not make a good tanker in arena and he can't produce that much damage in mid row. When your tanker dies off and he will tank for awhile (by the time his hp is lower than 50% or dying already).
Probably people will still using him with Leo + hyral for higher survival rate. (at least with this team still works decently). However most people will like to have hyral in Int team instead due to his skill buff Int team damage.

Now i only use him in treasure cave 

Jugo doesn't produce damage while being in mid (when he move to front, hes dying lol). Drop jugo and replace him with Naomi/Uldor/Booster to counter Blake.