Tempus

No coins on Roshar. Relatively little metal. Everything is gemstones, remember? Also - increasing weight changes the trajectory of flight, you couldn't hit a target in the air by compounding weight and pulling towards it. You would weight far too much. Especially since allomantic physics are pretty much newtonian - You can push off a coin since the coin hits the ground, but pulling a coin would need something solid enough to resist your momentum. Most likely scenario in that case is the inquisitor dropping like a rock and whatever bits of pullable metal simply being torn off the windrunner.

In WoR, it is told us that Aluminium is extremely rare on Roshar, and is mentioned that it only soulcast. It would take a large amount of advance preparation and the intervention of another Radiant or a Fabrial (both magic systems not mentioned in the original post as being available) to create weapons, armor, and any necessary gear out of aluminium.

Cstryon, to make it 'fair'... Knowing that the windrunner would have the full complement of his known powers - Stormlight enhancement (both physical enhancements and the mental enhancement that allows them to move with supernatural grace and skill), access to the three lashings, mutable shardblade and shardplate, and his host of squires as support... We need to look at trumps, really. Regular Atium burning is a trump, nothing the windrunner has can beat it. There are several compounding trumps, I think. Steel, Chromium, Duralumin, and probably Zinc. Actually, Zinc compound+electrum is basically atium, so yes, Zinc. Given how far compounding increases abilities over regular tapping, I think it would be difficult for a Radiant to overcome any of those. Besides those, I think the fight would tend to favour. The windrunner can fly, and so effectively retreat at any time. He also has support troops. He has merely to continue until he has the upper hand, retreating when necessary. The inquisitor, robbed of the above abilities, has no easy retreat from a windrunner. One interesting thing is that given how these things tend to work, I'm willing to bet that a Chromium burn would eliminate stormlight from the target.

A few things: Most importantly, I think - Steel Inquistors generally did not have feruchemical abilities. During the time that the steel ministry was active, the majority did not have feruchemy, and were unaware of compounding. Even once they began to take feruchemical powers, only a few learned to compound. If you're talking generic Windrunner versus generic Steel Inquisitor, I'd suggest that compounding is for sure out of the equation, and feruchemy is probably out as well. It would be probably be difficult to lash a burning allomancer. Lashing shardplate (much like pushing on metals attached to skin) is very difficult, but doable - it's theorized that the lashing must have more investiture (power) than the invested thing you are trying to lash. And then it seems to decrease the power of the lashing by the difference. It seems that it's much easier to gather investiture from Stormlight than metals, so that might not be as big a disadvantage as suspected. The Lashings do indeed require touch. The reverse lashing would still be useful against pushed projectiles, in the same way that Kaladin uses it to deflect arrows. The Shardblade seems to sever the spiritual link between a person and their limb. It's reasonably likely that increase of investiture in a person could repair the link, at the cost of the power required. That would mean any allomancy. It's almost certain that a Gold ferring could heal it. One thing to note is that basic abilities increase with Stormlight, and possibly all investiture. Brandon has suggested that the person's cognitive idea of themselves affects healing and ability enhancement when stormlight investiture is involved - how they view themselves. It's likely that ANY individual holding stormlight is at least as strong, fast, etc as an feruchemist tapping strength, speed, healing, and other physical things. An example: even Shallan can fall from large heights and be unscathed when holding just a bit of stormlight. Pewter allomancy, while it increases strength, is explicitly not terribly helpful in falling long distances (pushing against a coin to slow yourself or feruchemical weight tapping is used in-world for that purpose). So in general, I think the Steel Inquisitor would be outclassed. A knight radiant would be at least equivalent at all times in the physical aspects to the Inquisitor when he was burning, and actually likely be more effective due to a wider range of bonuses. Lastly, though - atium. A windrunner would have no counter for atium but to try to avoid being killed for as long as the atium burns. I personally feel like the outcome would basically be decided by how much atium the Steel Inquisitor could bring to bear in the match.

Allomantic chromium, Feruchemical duralumin. Duralumin is interesting in that it's one of the few ferrings that is just as useful while storing as it is while using. the description states that storing reduces awareness and friendship, which means you could be effectively invisible for a time while under maximum storage. Tapping makes people trust you more, and presumably enhances friendship. Frankly, it's a fantastic ferring power on it's own. Combining it with chromium should allow you to disable any opposing allomancer, through either sneaking or negotiation. It seems like the most effective way for a chromium allomancer to operate.