I've played a lot of these type of freemium "rpg" with energy system, and I honestly have to say Raid is one of the most generous in term of energy regen and bonus.
And, knowing how energy system works, I have to tell you that I have once hack the energy on some other games, and unlimited energy makes the games like this extremely boring.
And just a side suggestion, if you're an F2P or low spender, you want to progress slowly, focus on one goal one at a time.
And with Raid having multiple modes like campaign, dungeons, faction wars, clan wars and arena, it actually makes the goal setting easier. Because then you can switch to other modes when you're bored with the current plans you're focusing.
In short, this part of the game, the energy, Raid actually got it right.
Edit: BTW I am an F2P also, and to be honest for Raid, I don't think I ever felt that I need more energy, in fact at times I feel that there's just too much energy to spend, but maybe that's just because how I play the game in my own pace and I am not in a hurry to get to the "end-game" stage