Yeah, those are two things that have been bothering me from the time I started to use her.
In one hand, I save my team mates a lot of times and they also get kills, but not even an assist comes for me. For that reason, most of the time I feel like the money I spend on Meijar's Soulstealer is wasted. I mean, if i could get the assist, i could get at least twice the stacks i'm getting right now. And so, when you see my statics, it looks like I've been playing awfull.
And in the other hand, the money issue. Soraka wasn't made to kill (I got used to it), so you get a very low ammount of money, and that delays your build making a lot. And worst, if the game becomes long, I get the feeling that I'm useless because everybody has huge amounts of life, or they do such big damage in a short time that when I cast Astral Blessing, it heals such bit of their health bars.
To solve this problem, I use Starcall on minions to kill them all and get the money, but the truth is that this skill sucks like hell. At level 18, with Zhonya's Ring, I can't manage to kill them in one hit. And why do I have to get SOOO close to cast it? Sounds like a joke...
I think that buying items that give you money per second would help, but I tried it sometimes and I'm still not convinced with how it works.
I think that healing others' life and mana should give small ammounts of gold, and specially, exp. I'm getting tired of being always so low leveled compared to the rest of the 9 players, because the only way of getting exp is killing.