Not a single one of them is worth the time or effort it takes just to find people to group with, and 4-mans aren't worth the time it takes to do them. Here's why.
1. It's been implied that Heroic's are extra content, and no one's making you do them. This is far from true. In order to get enough commendations for gear or mods, you have to do Heroics. The drop rate for those commendations and the amount you get from regular quests is next to nothing. On some planets, this is not that big a deal. But on others, like Balmorra Empire side, ALL of the Heroics are 4-mans. And outside the starter zones, there are 4+ every planet.
2. Heroics are not designed to be done solo, in more ways than one. Before 1.2, most Heroics could be soloed simply by stripping off all gear with durability on it and suicide-running through mobs to get to whatever object needed to be grabbed or whatever button needed to be pushed. The companion could be used as bait if need be. But, BioWare went and made it so none of those things could be picked up while in combat, and also made it so that members of mob groups would respawn after only a few minutes if the entire group was not killed.
Dailies should be designed to be done quickly and given rewards directly related to the effort it takes to do them. 2-3 commendations out of the 120 I want to get for an earpiece after spending two solid hours finding a group and running the Heroic comes nowhere near worth my effort. Also, BioWare, I don't know what customers you're trying to cater to, but I'm willing to bet the ones who play the 7-8 hours a day you're expecting do not make up the majority of your player base. Why? Because the ones who make enough money to have cash to blow on a monthly subscription for a video game have actual jobs. I work ten hour days, five days a week, not counting the time it takes me to drive home, work out, shower, dinner, and then there's the six hours of sleep I need to function as a productive non-violent member of society. This leaves three hours tops on weekdays for me to play your game, and that's if I decide I want to play SWTOR. And this is coming a single mid-20s male.
According to this http://www.theesa.com/facts/gameplayer.asp
the average gamer is middle-aged. The average middle-aged person has a full time job, spouse, kids, and all that mess. Those people screwing around on the Internet 7-8 hours a day are frowned upon. The stereotypical gamer is an overweight greasy sack of crap hiding out in a basement while screaming for Mom to bring down more Cheetos. Nobody wants to be that guy, because everybody laughs at that guy. Also, that guy is also the stereotypical Internet troll, and you don't want them. They're ugly and smell funny.
When I log into SWTOR, I have one of three goals: Level an alt, run some PvE or PvP, or grind dailies. I only play maybe four hours tops, including weekends. Either I'll get bored and decide to find something else to do with my day, or I'll get stuck on something and grow too frustrated to play anymore. But every time, without fail, literally since the day I got into Early Access, it takes a minimum of an hour to get a group for a 4-man. I have a guild, my server population is high, I use General chat, I use your LFG tool, I'm nice, polite, courteous, patient, acting like the well-groomed Southern gentleman Daddy beat into me, and that's how long it takes me to scrape up three people to help out. It's just not worth it, and it truly saddens me, because I want it to be.
Suggested fixes: Give people more reason to do them, other than being self-entitled completionists like me. Up the reward to 5 commendations. Hide datacrons inside them, I've seen that done a few times already. Get rid of that respawn thing, or increase the timer. Give companions a considerable buff, especially tanks and healers. Not enough to let us faceroll God and every angel He has, but enough so that one can sub for another player if need be.
You can keep the out-of-combat restriction, I always figured that was intended anyway.