In a 3025-era fight, a Commando makes a great escort for heavier units. Very few people will try to close with your Zeuses and Archers after you play a game or two where they're escorted by a Commando carrying nothing but infernoes. }:)
As others have said, to keep this thing alive in a straight fight, you keep it in reserve until the enemy big boys are engaged with your heavies, then dash the COM out to sow chaos. Heck, this'll still serve you well up through the Clan invasion, as Clan warriors are likely to dismiss such an insignificant target, and those missiles(inferno or otherwise) are a great way to wear down an Elemental point fast. Dash the COM out when the time is right, then stay at top speed and run from one BA point to the next, pumping a single heavy salvo into each one in sequence, leaving them vulnerable to lighter weapons so the heavies can finish them with secondary shots instead of having to focus their attention on them and letting the OmniMechs have their way. This gets much riskier in modern games, where other 'mechs can afford to distract themselves for the single turn it takes to cripple the Commando, and battle armor is increasingly able to take one on head on and come out the winner.
Honestly, your best bet for using a Commando properly is to print out the record sheet, then cross out the name. Underneath, write in COM-2D Sneaky Midget Bastard. This'll put you in the right frame of mind for properly using one.