First of all, don't raise your Ranged and Magic as they won't raise your Combat from your current stats. I would try raising my Prayer to 70 for Piety, as well.
Firstly, there are 4 spots. 3 of which you don't need prayer. The 4th is in the pub. Use prayer or keep guthan's on the either time and stand in corners so you don't get piled. I can show you in-game if you PM me here.
Secondly you can,
1. Bring noted food, sell it to the general store there and buy it back. It'll be unnoted.
2. Bring Guthan's to heal yourself
3. Bring prayer potions and bank when you've finished. You can do option 1 with prayer potions, but it's alot more expensive. I recommend banking.
Get 80 Attack 80 Defence 70 Prayer Then keep you Strength , Magic and ranging level the same! so they dont cancel eachother out when leveling , so you gain Cmb levels more fast