Yes. The usual method is a sliding net shutter that runs on its own track parallel to the glass, so you slide the net across whichever part of the window is open. The frame needs a track or a built-in mosquito frame for it, which is why it is best decided when the window is ordered.
Fibreglass is the common default: it does not rust and costs less. Stainless steel (SS 304) lasts longer, resists pets and rodents, and handles coastal salt air. Aluminium mesh suits inland homes but can show white powder near the sea. Avoid nylon and cheap galvanised iron where sun or salt is strong.
A little. A standard insect screen of about 18 x 16 strands per inch loses little airflow while stopping mosquitoes, flies and lizards. Finer mesh that also stops midges and sandflies cuts the breeze more. Keep nets clean, because dust clogging the mesh reduces airflow further.
Vacuum or soft-brush it about once a month and wash it with mild soapy water each season. Do not pressure-wash fibreglass. Clean the track and brush seals too, because sliding nets gather grime fastest in the monsoon. Check the spline and corners before the rains begin.
For a standard sliding door, an integrated flyscreen running in the door frame works well. For a wide balcony or folding door, a pleated or retractable net is the usual answer, since a single rigid mesh frame cannot span the opening. Ask about the net when you order the door.
Nets do not prevent dengue on their own. The World Health Organization lists window screens among personal protection measures and notes that dengue mosquitoes bite during the day. It also advises covering, emptying and cleaning water containers weekly. Treat nets as one layer of protection.
Often, yes. Some frames allow a mosquito frame to be added later; AluK India says this for its SC40 series using two profiles. Where the frame has no room for a mesh track, a pleated, retractable or magnetic net fixed to the opening is the usual alternative. A site check tells you which applies.