Is being an excellent debater who is able to present his case clearly, succinctly, and compellingly a qualification for ministry in the church or is it a handicap or disqualification?
I guess it would depend on which ministry within the church.
If you're the flower arranger or the guy who sweeps the floor it's maybe not hugely important. But if you're the guy giving a sermon you really need to be able to get your point across in a way that people will understand. Being a debater isn't important - I don't know very many people who were successfully debated into the kingdom of God - but if you can't give a sermon that's clear and reasonably concise maybe you shouldn't be preaching. I know I've sat through a few sermons where I listened for 20-30 minutes and when the speaker stood down from the pulpit I still had absolutely no idea what, if any, point he was trying to make.
One guy I met briefly a few years ago is an excellent debater. He's a Christian minister who is also qualified to be an imam because he has a near encyclopedia knowledge of the Qu'ran. He often debates Muslims in public settings and generally they can't counter his arguments. He has been known to preach the gospel of Jesus Christ using only the Qu'ran. It's hard to see him doing what he does successfully without really good skills in debating - knowing his subject matter well and thinking on his feet.
In that regard being "an excellent debater" often means little more than having a deep enough knowledge of the subject matter and being able to apply it to situations on the fly, in which case it would appear that both would be great assets for a minister. It's disappointing (although thankfully rare, for me at least) to sit through a sermon and realise that the speaker made a case using their chosen verses but other verses paint a very different picture. It would be disappointing to seek out advice from an elder or minister only for them to have little to offer but then approach me with a few Bible verses a week later.
I realise Paul is talking about bishops here, but it seems relevant (emphasis is mine):
Tit 1:7-9 NKJV For a bishop must be blameless, as a steward of God, not self-willed, not quick-tempered, not given to wine, not violent, not greedy for money, (8) but hospitable, a lover of what is good, sober-minded, just, holy, self-controlled, (9) holding fast the faithful word as he has been taught, that he may be able, by sound doctrine, both to exhort and convict those who contradict.
