It's now safe to invest, yes.
We are developing the script so it can handle more frequency and load hence it skipped a few investments in the past
Skipped investments will still be paid. A few people have tried to extort us of free BTC so if you have been paid already or are in the queue (or showing fake TXID's) I guarantee you will not be paid in the future.

Tl:dr if you are not in the queue you will still be paid. Don't worry about it