Please give me sources. Thanks.

Olam ha-ba (if it's be-meizid)?

Thank you.

an arel on purpose- can he be counted in a minyan? get an aliyah? I know the ramifications when there was a beis hamikdash. What are the modern day ramifications?

bump

What's an arel?

I haven't found a searchable Shulchan Aruch, but the Mishne Torah at http://kodesh.snunit.k12.il/ is searchable. Didn't find anything applicable today for ערל, but since an uncircumcised kohen can't do avodah in the Beit Hamikdash, perhaps he can't do birkat kohanim in shul. I didn't find anything else that I could see a way to apply today.

Someone with an intact foreskin.

See here in the Chatam Sofer 6 [Likutim] Responsum 12, in the third paragraph, beginning with the words, "Ve-hineh me-reish..."

[attachment=2457:x0876.pdf]

See also here in the Eliyahu Rabba in his comments to the Levush Orach Chaim 128:
[attachment=2458:ER_128.pdf]

could someone summarize?

Depends whom one asks.

But the point is that p_almonius is correct in that there are poskim who extrapolate from an arel not being fit for the avodah to his not being fit to duchen.

and that's all?

basically, yeah. it depends whom one asks if an arel can duchen, with some saying yes and some saying no, depending if fitness for duchening is derived from laws concerning fitness for the avodah. That's my summary to the best of my limited understanding.

But note the question they are dealing with is not a meizid, but let's say someone who cannot be circumcised, like if his older brothers had died as a result. If a kohen is refusing circumcision be-meizid, that opens the question of that makes him a mumar, because generally a mumar is forbidden to duchen.