Besides that you need a 6th item insted of Doran's Blade dude. lol ^^

If the enemy team has a jungler, you would never max out Make it Rain, besides that, its a ****ty ******** ****ing spell really, you only really use it for the slow and "oh no im taking dmg from bullets" harrash factor it has.
Double up as main ability? GO GO GO! since people on mid og side lanes NEVER get the fact that they stand behind a minion and is hterefor inihalated by the shot - and the dmg.. WOW! + Impure shots are great for harrashments with 2 or 3 shots after one of each other on the target. If you like, at mid, pew pew your target up a bit, dont hesitate to harrash like hell with Impure shots passive and finish of with a Double Up. Turns out, that with these 2-3 seconds spend on hammering the enemy, he/she will get down to 50% + - hp. Who doesn't want that? :)

I like your guide , so + from me. BUT! MF is really squishy with no potential hp or lifesteal, so if you aren't a big fan of crit combined with Infinity Edge, go for som attack speed and lifesteal - it works out really well when ganked, ganking, team fighting or just 1v1'ing. Lifesteal and attack speed saves your day, a lot, and I cant say that enough really.
After all, good guide mate, keep it up. :)

looks good but I gotta say I think MIR can be an effective early game harassing/farming tool. I'll often level up MIR and Impure shots, you knock out those creep waves almost instantly at level 4~5 and with a few Mana runes you can use it every time it's up. this gives you tremendous pushing ability and lane control. its also great for forcing the enemy back and denying them gold/xp. When they get a little low hit them with the slow, pop impure shots and exhaust you can usually finish off most carries before the exhaust even wears off. the rushed infinity edge is nice I do that alot but I'll often pickup a vampiric scepter as well for some sustain and build that into a blood thirster later depending on the enemy team makeup.

Her Q is certainly a great harass tool but the problem with Q over E is that Q will cause enemy minions to aggro you, Make it rain causes no minion aggro so this is an important thing to keep in mind as well.

Overall good guide, +1!

Best MF guide I've seen so far. Keep up the good work man!