No, they are not "safe", as none of the typical round cells we use for vaping are intended to be used outside a fully protected battery pack with a protection circuit. There are certain things that we can do to make them safer. That is, safer than the level of risk we find to be the maximum acceptable level, which, due to to fact that everyone is responsible for his/her own safety, should be viewed as just a guideline or starting point to recommend to people who ask how much is safe. There are no hard and fast numbers that either are safe or are unsafe to vape. The general consensus among professional experts in battery technology is that the Samsung 30Q can handle up to 45 watts per battery in a regulated mod reasonably safe. So, up to 90 watts with a pair of 30Q batteries in a dual battery regulated mod such as the Aegis Legend.
As for the Molicel P26A. In the Aegis Legend, in terms of how much vaping time you'll get before you need to recharge the batteries again, it will noticeably outperform the Samsung 30Q excepting only if you vape at several watts below 60 watts, which is where they will perform about equal despite the P26A will age slower mainly as a result from it heating itself up less. At even lower wattages is where the 30Q wins. Also keep in mind that either 1/ having to recharge your batteries more frequently due to them giving you less vaping time or 2/ using up a larger portion of their discharge cycle due to them lacking the capability to deliver as much energy compared to a different choice of battery causes faster battery aging too─which is in addition to faster battery aging resulting from letting batteries run warmer─plus extra wear and tear caused on the battery door and battery contacts of the mod if you end up changing out the batteries more frequently. Up to 75 watts per battery (so 150 if the mod uses two batteries) is considered within reasonable safety limits for the Molicel P26A. Above that, go with the Samsung 20S.