1. you take a risk but it ends in a loss or;
This is one of the things that I have considered when I've taken risk not only in investing but also in other decisions I've made in my life. Mistakes and losses can be recovered if I am eager to do it and I can reason to myself that 'at least I've tried' than regretting that I never did.
2. you play safe but after time you see that you could have made profit if you took that leap
This is applicable more for the younger generation or at age. You've got ample time to recover if ever things didn't go well with your decisions but those that are in the veteran's age, there is no room for mistake anymore or if there is, only a little.
the first one could be more painful because you lose some money after believing that you could have find success in engaging in a specific project but the second one could also be more painful because you will be plagued with what if's but at least you would not have lost some money you just simply did not gain anything
what decision would be harder to live with?
Both are painful when you're not prepared and not used to taking risk. Playing safe is fine but you've got to take some risk still even with that, you only minimize and mitigate the risk you take.