Re: A guide to Lina Inverse
I have wrote a Lina guide before (well I didn't really get it published I don't think, too busy at the time to completely finish, I wish I would've kept it and posted it for real now that I have the free time). I disagree with an early point of Fiery Soul. A point of Fiery Soul lvl 4 is as useful as a point in Stats; you should be concentrating on your nuke damage, not getting in 1 or 2 extra hits (which would be the equivalent of a point in DS or LSA). All in all; FS does little to nothing as far as a lvl 1 skill goes, it should be skipped until your others are maxed out. I have started to try out new stuff with Lina, and I agree that maxing out DS with 2 LSA points (considering you took out your FS point) is the best way to go.
Besides that, pretty similar builds, though I wouldn't put Desolator. As I have said, experimented more in the ways of Lina, all I can say is that DPS Lina is almost never worth it (if you're in -EM, possibly) and/or you will almost never get up to that point unless you have a lot of disables on your team. A good opposing team will take you out among the first if you go for DPS, you would need BKB first to get an item like Desolator to actually do some DPS damage, which (like I said) is something that you won't ever get to (at least you SHOULDN'T).
Also, as I look at your Point Booster I thought to myself; wouldn't it be more worth it to grab a Bracer/Null or two in the early game stages? Sure it's a good filler item for the quick boost, but you won't use it in any item (thankfully you didn't put Aghanim's Sceptre as a core/luxury item like some people), and the fact that you will need the help of a Bracer/Null for early last hitting. Let's compare these towards Point Booster:
Bracer vs. Point Booster: You get 28 more HP, 6 more damage, and 0.6 more armor, and 6% more AS, costs 180 less gold. Easy buildup and you might get (on a low average guesstimation) 8 more creep kills than without anything except +3 damage/3% AS with Wand, which would translate to (on average guesstimation) 392 gold, making it much more worth the Point Booster. It could possibly hook you a kill as well.
Point Booster vs. Bracer: You get 72 more mana, equivalent to about the mana of a Dagger blink. One less item slot filled. I'd rather go with the Bracers/Nulls usually, but that one less item slot filled is sometimes a winner.
Null vs. Point Booster: Same as Bracer except costs 230 less gold, the Point Booster bonus would be opposite (change 72 mana to 72 HP, meaning more mana with Nulls).
I'd say it's a matter of need and personal preference. I think you would be good with just 1 Bracer for the game, that's why you have Wand AND Bottle, no?