It's a hospital ship. So, are you losing all weapon systems or are you retaining purely self-defence systems, & are they only passive or are you including active systems? (Remembering some anti-shipping weapons use active weapons-targetting systems as a lock-on beacon in passive approach mode.)
Standard navigation radar is, obviously, a must & I'd definitely retain the AN/SLQ-49 Chaff Bouys, MK-36 Chaff Launcher & AN/SLQ-25 NIXIE Towed Torpedo Countermeasures systems as passive defence systems. In this configuration, either the AN/SLQ-32(V)2 or AN/SLQ-32(V)3 Electronic Warfare (EW) system, too.
If you're going with active defence systems I'd lose the Sea Sparrows & rely on CIWS's, for example 4 x 20mm Mk 15 Phalanx &/or 4 x 30mm Goalpost systems. Plainly all-CIWS's is not an optimal defence package but they are purely self-defence systems, which means they should be mildly OK under the Geneva Conventions. In this configuration, definitely the AN/SLQ-32(V)3 Electronic Warfare (EW) system.
Oh, & you'll want an air-search radar to manage air traffic to & from the flight deck.

Guy
You raise some interesting questions. From what I've read here:
http://en.wikipedia.org/wiki/Hospital_ship........there is a brief sentence near the bottom that reads:
Armed vessels are disqualified from protection as a hospital ship under international law.
But, does that refer to "offensive" armament, or "defensive" armament, or both? I would tend to think it means both. But what if a hospital ship has been boarded by hostile forces? What then? Certainly the crew should have small arms to defend itself?
I am most likely not going to put ANY armaments, offensive or defensive, on my model ship. I "might" put the pedestal and gun shields in various locations for .50 cal guns, but not add the actual guns themselves. I want to build this model as "technically believeable" as possible and stick to international laws, i.e. no armaments.
As far as radars and electronic systems go, I would probably keep the air search, surface search, and navigation radars. I doubt a hospital ship would need an ECM system and chaff launchers. I don't know if "defensive armaments" like NIXIE, chaff, SLQ-32, etc. would disqualify a hospital from protection under international law. I'm guessing they would because the RFA Argus:
http://en.wikipedia.org/wiki/RFA_Argus_%28A135%29.......has defensive armament and is not protected from international law per this:
The British Royal Fleet Auxiliary ship RFA Argus would be a hospital ship were it not for its armaments.
I like it any way you look at it ! I like having boats hidden inside, or under sponsons. But at 350 scale seeing as much out in the open would also be good....
Putting extra boats inside might be nice, but in a real world situation, it's not practical as you have to move the boats to an exterior position which adds extra time.