looking for backpacking routes that give alpine feel

I assume you are asking about the mid-atlantic region since you are asking in this forum.Two areas I would often head to in the summer months for water,views and scrambling were Saint Mary's Wilderness and Goshen Pass N.A. in central Va.Most(but not all) of the scrambling at both locations will be off trail and Saint Mary's definitely has enough trails for your criteria while Goshen is close enough it might be best done as an overnighter or day hike in combination.I lived close enough that I would do day hikes at either mid week as the more popular areas near the front country at each can get crowded on weekends.

For the most alpine feel I would look at Mt Rogers N.A./Grayson Highlands in southwest Va,but it doesn't as closely meet your other criteria(the areas near vehicle access can also get crowded on summer weekends here as well).

If you are interested in any of these I can provide some links I have on details and I have explored all three extensively in the past...

Check out Dolly Sods and Roaring Plains, maybe North Fork Mtn in WV. Northern half of Standing Stone Trail in PA has tons of views, extensive ridge with many views, rocks, historical features, sinkholes, rock formations. Otherwise, you'll want to go to the Adirondack high peaks, though mid June may still be black fly season.

For Grayson Highlands, the state park area will likely require reservations but most of the adjoining area is Mt. Rogers NRA which is part of the Jefferson NF so will not require reservations and have fewer restrictions other than not camping on certain environmentally senstive areas such as on Mt Rogers itself.Since the state park area is where the crowds congregate I never spent must time there except on the A.T. through the area and perhaps a brief side trip along a stream/small waterfall area(Wilson Creek)just so I could say "been there,done that"

I would usually start at the A.T. crossing of Rt 603(convenient coming in from the north) and hike up Pine Mtn. camping at the first A.T. shelter if arriving late(which was the usual case),though from recent reports there may be some concern about leaving vehicles at remote parking lots around there these days(though I always prefer to be the one not leaving a sleeping bag visible in the back seat).