In this case, it will create fresh short position. Also, these orders are valid only for a day, if not executed they will automatically vanish at the end of the day after market closes.
If you want orders for multiple days, you can explore GTT. You can learn more below post.
The SL-M Order cannot be placed at price higher than LTP, the price should be lower than LTP. If you want to Sell at price higher than LTP, you will have to use Limit Order.
If there are sellers at that price it will execute. Also, limit order allows you to buy or sell a stock at the price you have set or a better price. For your Limit Sell Order, it will execute at limit Price or higher (since it is better price) but not lower than your limit price (since it isnβt better).