I am considering hiking rinjani in a few days and was wondering if the summit has recently been reopened? Also I want to do this hike unguided, I am aware I will need to carry my own things which is not an issue for me, is this possible and if so where do I begin the trek?

I plan on doing a solo 1 day round trip to the crater rim in mid August. Do I need a jacket at that elevation? (What is the temperature?) I am reasonably fit and run long distances every weekend and also take part in half marathons throughout the year. I also do uphill hikes once in a while, covering distances of over 10 miles and elevation of around 1200 meters. So, stamina is not an issue. Just wondering about altitude sickness since it is straight up without acclimatization. Would running shoes suffice or should I bring my hiking boots. I am trying to travel as light as possible. Hydration wise, I have a 2 liter runners hydration backpack and a runner's hydration belt that takes 2 small bottles of water. Can also stuff additional bottles in my backpack. Any place to refill along the way on the posts?

I would like to do this trek but I do not have a pair of walking boots with me. Is there a possibility of renting / hiring good quality boots for the trek?