Not playing Magic

Well, a few months ago now, I gave up and did something that I swore I would never do again.  I played Magic the Gathering.  I was at the store, they had a spare seat at a modern tournament, someone lent me a deck, and the rest is history.  I've now started playing again, and in the few drafts I've played in mid table mediocracy has been my fate.  I've also started collecting a few cards, and have a standard red rush deck that has not been terrible in casual games, although I've not managed to test in competitively.  One thing that I do know, however, is that it is not even close to being ready for modern, even with a few cards swapped out.

Modern is a format that I should have been at home in.  Older cards, some of which I knew.  And yet, it seems to me that it is even more open to abuse than the old Type I used to be back when I played competitively (around Unlimited-6th).  3-4 turn kills were common, and while I accept that my deck was vastly underpowered against these, there should have been something I could have done.  I'm not sure that this is a format that I would have enjoyed, even if I did have the card pool.

So, my deck so far consists of

16 Mountain
4 Wind-Scarred Crag
4 Bloodfire Expert
4 Bolt of Keranos
2 Dragon Fodder
2 Foundry Street Denizen
2 Gore Swine
3 Lightning Berserker
4 Lightning Strike
4 Mardu Scout
1 Monastery Swiftspear
4 Spark Jolt
1 Trumpet Blast
4 War-Name Aspirant
3 Wild Slash
2 Zurgo Bellstriker
Sideboard:
2 Arrow Storm
4 Barrage of Boulders
1 Demolish
2 Pyrotechnics
3 Roast
3 Shatter

I'm sure that it has hundreds of holes.  I know that it is weak against lots of deck types.

What I do wonder is, in the absence of the opportunity to spend hours playtesting face to face, what engines online people use to test decks?